Add Alternate Files With vim-rails as a vim til.

README.md

@@ -143,6 +143,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 
 ### vim
 
+- [Alternate Files With vim-rails](vim/alternate-files-with-vim-rails.md)
 - [The Black Hole Register](vim/the-black-hole-register.md)
 - [Buffer Time Travel](vim/buffer-time-travel.md)
 - [Check Your Current Color Scheme](vim/check-your-current-color-scheme.md)

vim/alternate-files-with-vim-rails.md

@@ -0,0 +1,11 @@
+# Alternate Files With vim-rails
+
+If you are doing a good job of testing all the code you write in a rails
+project, then most of your code files should be paired with test (or spec)
+files. You can think of these as alternate files. The alternate file of
+`user.rb` is `user_spec.rb` and vice versa.
+
+The [`vim-rails`](https://github.com/tpope/vim-rails) plugin makes it easy
+to jump back and forth between alternate files. Enter `:A` and you will go
+to the alternate file of the current file. This makes a common navigation
+path for rails projects all the more efficient.