Update readme

- cite rtweet!
- general formatting
- gathertweet timeline

README.Rmd

 ```{r setup, include = FALSE}
 knitr::opts_chunk$set(
   collapse = TRUE,
+  cache = TRUE,
   comment = "",
   prompt = TRUE,
   fig.path = "man/figures/README-",
 ```
 
 [rtweet]: https://rtweet.info
+[cron]: https://en.wikipedia.org/wiki/Cron
 
-# gathertweet
+<h1 style="font-weight: normal;">gathe<strong>rtweet</strong></h1>
 
 The goal of gathertweet is to provide a simple command line utility that wraps key functions from [rtweet].
 
-The magic of **gathertweet** is that it grants you the power to **quickly set up twitter monitoring and tweet gathering** while saving you from the pain of **writing a bunch of boilerplate code to save new tweets without losing previously collected tweets, join multiple searches, update tweet stats, simplify stored tweets, and more**.
+The magic of **gathertweet** is that it grants you the power to **quickly set up twitter monitoring and tweet gathering** while saving you from the pain of **writing a bunch of boilerplate code** to 
+
+- save new tweets without losing previously collected tweets, 
+- join multiple searches, 
+- update tweet stats, 
+- simplify stored tweets,
+- schedule easily with [cron],
+- and more...
+
+gathe**rtweet** is a thin wrapper around [rtweet], the excellent R interface to Twitter written by [Mike Kearney](https://mikewk.com/).
+If you use gathertweet, please ensure that you [cite rtweet directly](https://rtweet.info/authors.html).
+
+```{r}
+citation("rtweet")
+```
 
 ## Installation
 
 ```
 
 which adds `gathertweet` to `/usr/local/bin` as a symlink (you can adjust where this link is created in `install_gathertweet()`).
-If you need admin rights to install, try `sudo Rscript -e "gathertweet::install_gathertweet()` from the command line.
+If you need admin rights to install, try 
+```
+sudo Rscript -e "gathertweet::install_gathertweet()"
+``` 
+from the command line.
+
 
 ## Example
 
+### Use gathertweet from the command line
+
 Create a directory to store tweets
 
 ```bash

README.md

 
 <!-- README.md is generated from README.Rmd. Please edit that file -->
 
-# gathertweet
+<h1 style="font-weight: normal;">
+
+gathe<strong>rtweet</strong>
+
+</h1>
 
 The goal of gathertweet is to provide a simple command line utility that
 wraps key functions from [rtweet](https://rtweet.info).
 
 The magic of **gathertweet** is that it grants you the power to
 **quickly set up twitter monitoring and tweet gathering** while saving
-you from the pain of **writing a bunch of boilerplate code to save new
-tweets without losing previously collected tweets, join multiple
-searches, update tweet stats, simplify stored tweets, and more**.
+you from the pain of **writing a bunch of boilerplate code** to
+
+  - save new tweets without losing previously collected tweets,
+  - join multiple searches,
+  - update tweet stats,
+  - simplify stored tweets,
+  - schedule easily with [cron](https://en.wikipedia.org/wiki/Cron),
+  - and more…
+
+gathe**rtweet** is a thin wrapper around [rtweet](https://rtweet.info),
+the excellent R interface to Twitter written by [Mike
+Kearney](https://mikewk.com/). If you use gathertweet, please ensure
+that you [cite rtweet directly](https://rtweet.info/authors.html).
+
+``` r
+> citation("rtweet")
+
+To cite rtweet use:
+
+  Kearney, M. W. (2018). rtweet: Collecting Twitter Data. R
+  package version 0.6.7 Retrieved from
+  https://cran.r-project.org/package=rtweet
+
+A BibTeX entry for LaTeX users is
+
+  @Manual{rtweet-package,
+    title = {rtweet: Collecting Twitter Data},
+    author = {Michael W. Kearney},
+    year = {2018},
+    note = {R package version 0.6.7},
+    url = {https://cran.r-project.org/package=rtweet},
+  }
+```
 
 ## Installation
 
 
 which adds `gathertweet` to `/usr/local/bin` as a symlink (you can
 adjust where this link is created in `install_gathertweet()`). If you
-need admin rights to install, try `sudo Rscript -e
-"gathertweet::install_gathertweet()` from the command line.
+need admin rights to install, try
+
+    sudo Rscript -e "gathertweet::install_gathertweet()"
+
+from the command line.
 
 ## Example
 
+### Use gathertweet from the command line
+
 Create a directory to store tweets
 
 ``` bash
 
 ``` bash
 > gathertweet search --n 100 --quiet "#rstats"
-[2019-01-29 21:54:37] [INFO] ---- gathertweet search start ----
-[2019-01-29 21:54:37] [INFO] Searching for "#rstats"
-[2019-01-29 21:54:37] [INFO] Gathered 100 tweets
-[2019-01-29 21:54:38] [INFO] Total of 100 tweets in tweets.rds
-[2019-01-29 21:54:38] [INFO] ---- gathertweet search complete ----
+[2019-05-04 14:52:15] [INFO] ---- gathertweet search start ----
+[2019-05-04 14:52:15] [INFO] Searching for "#rstats"
+[2019-05-04 14:52:16] [INFO] Gathered 100 tweets
+[2019-05-04 14:52:16] [INFO] Total of 100 tweets in tweets.rds
+[2019-05-04 14:52:16] [INFO] ---- gathertweet search complete ----
 ```
 
 Get more tweets, automatically starting from end of the last search
 
 ``` bash
 > gathertweet search --n 100 --quiet "#rstats"
-[2019-01-29 21:55:39] [INFO] ---- gathertweet search start ----
-[2019-01-29 21:55:39] [INFO] Searching for "#rstats"
-[2019-01-29 21:55:39] [INFO] Tweets from 1090438050835038208
-[2019-01-29 21:55:39] [INFO] Gathered 1 tweets
-[2019-01-29 21:55:39] [INFO] Total of 100 tweets in tweets.rds
-[2019-01-29 21:55:39] [INFO] ---- gathertweet search complete ----
+[2019-05-04 14:53:17] [INFO] ---- gathertweet search start ----
+[2019-05-04 14:53:17] [INFO] Searching for "#rstats"
+[2019-05-04 14:53:17] [INFO] Tweets from 1124748486971359232
+[2019-05-04 14:53:17] [INFO] Gathered 1 tweets
+[2019-05-04 14:53:17] [INFO] Total of 100 tweets in tweets.rds
+[2019-05-04 14:53:17] [INFO] ---- gathertweet search complete ----
 ```
 
 Update the stored data about those \#rstats tweets
 
 ``` bash
 > gathertweet update
-[2019-01-29 21:55:40] [INFO] ---- gathertweet update start ----
-[2019-01-29 21:55:40] [INFO] Updating tweets in tweets.rds
-[2019-01-29 21:55:40] [INFO] Getting 100 tweets
-[2019-01-29 21:55:41] [INFO] ---- gathertweet update complete ----
+[2019-05-04 14:53:18] [INFO] ---- gathertweet update start ----
+[2019-05-04 14:53:18] [INFO] Updating tweets in tweets.rds
+[2019-05-04 14:53:18] [INFO] Getting 100 tweets
+[2019-05-04 14:53:19] [INFO] ---- gathertweet update complete ----
 ```
 
 ``` bash
 > ls -lh
 total 40K
--rw-rw-r-- 1 garrick garrick 40K Jan 29 21:55 tweets.rds
+-rw-rw-r-- 1 garrick garrick 39K May  4 14:53 tweets.rds
+```
+
+Gather user timelines
+
+``` bash
+> gathertweet timeline hadleywickham jennybryan dataandme
+[2019-05-04 21:11:54] [INFO] ---- gathertweet timeline start ----
+[2019-05-04 21:11:54] [INFO] Gathering tweets by hadleywickham, jennybryan, dataandme
+[2019-05-04 21:12:23] [INFO] Gathered 7368 tweets from 3 users
+[2019-05-04 21:12:23] [INFO] Total of 7368 tweets in tweets.rds
+[2019-05-04 21:12:23] [INFO] ---- gathertweet timeline complete ----
+```
+
+### Schedule tweet gathering using cron
+
+The primary use case of gathertweet is to make it easy to set up
+[cron](https://en.wikipedia.org/wiki/Cron) to periodically gather
+tweets. Here’s a simple example to download all tweets matching the
+search term `rstats OR tidyverse` every night at midnight. The tweets
+are stored, by default, in `tweets.rds` in `~/rstats-tweets`.
+
+``` bash
+crontab -e
+
+# m h dom mon dow   command
+0 0 * * * (cd ~/rstats-tweets && ~/bin/gathertweet search --polite 'rstats OR tidyverse' >>gathertweet.log)
 ```
 
 ## Documentation
     
     Usage:
       gathertweet search [--file=<file>] [options] [--] <terms>...
+      gathertweet timeline [options] [--] <users>...
       gathertweet update [--file=<file> --token=<token> --backup --backup-dir=<dir> --polite --debug-args]
       gathertweet simplify [--file=<file> --output=<output> --debug-args --polite] [<fields>...]
     
       --backup              Create a backup of existing tweet file before writing any new files
       --backup-dir <dir>    Location for backups, use "" for current directory. [default: backups]
       --debug-args          Print values of the arguments only
+      --and-simplify        Create additional simplified tweet set with default values.
+                            Run `gathertweet simplify` manually for more control.
     
-    search:
+    search and timeline:
       -n, --n <n>           Number of tweets to return [default: 18000]
-      --type <type>         Type of search results: "recent", "mixed", or "popular". [default: recent]
       --include_rts         Logical indicating whether retweets should be included
-      --geocode <geocode>   Geographical limiter of the template "latitude,longitude,radius"
       --max_id <max_id>     Return results with an ID less than (older than) or equal to max_id
+    
+    search:
+      --type <type>         Type of search results: "recent", "mixed", or "popular". [default: recent]
+      --geocode <geocode>   Geographical limiter of the template "latitude,longitude,radius"
       --since_id <since_id> Return results with an ID greather than (newer than) or equal to since_id,
                             automatically extracted from the existing tweets <file>, if it exists, and
-                            ignored when <max_id> is set. "none" for all available tweets. [default: last]
-      --and-simplify        Create additional simplified tweet set with default values.
-                            Run `gathertweet simplify` manually for more control.
+                            ignored when <max_id> is set. Use "none" for all available tweets,
+                            or "last" for the maximum seen status_id in existing tweets. [default: last]
+    
+    timeline:
+      --home                If included, returns home-timeline instead of user-timeline.
+    
     simplify:
       --output <output>     Output file, default is input file with `_simplified` appended to name.