Update the plugins managment. Add the function 'omz-plugin' (inspired from bash-it)

plugins/available/rake-fast/README.md

@@ -0,0 +1,35 @@
+# rake-fast
+
+Fast rake autocompletion plugin.
+
+This plugin caches the output for later usage and significantly speeds it up.
+It generates a `.rake_tasks` cache file in parallel to the Rakefile. It also
+checks the file modification time to see if it needs to regenerate the cache
+file.
+
+This is entirely based on [this pull request by Ullrich Schäfer](https://github.com/robb/.dotfiles/pull/10/),
+which is inspired by [this Ruby on Rails trick from 2006](http://weblog.rubyonrails.org/2006/3/9/fast-rake-task-completion-for-zsh/).
+
+Think about that. 2006.
+
+----------
+
+Since August of 2016, it also checks if it's in a Rails project and looks at
+rake files inside `lib/tasks` and their modification time to know if the
+cache file needs to be regenerated.
+
+## Installation
+
+Just add the plugin to your `.zshrc`:
+
+```zsh
+plugins=(... rake-fast)
+```
+
+You might consider adding `.rake_tasks` to your [global .gitignore](https://help.github.com/articles/ignoring-files#global-gitignore)
+
+## Usage
+
+Type `rake`, then press tab.
+
+If you want to force the regeneration of the `.rake_tasks` file, run `rake_refresh`.