Extract contribution guidelines

README.markdown

@@ -105,29 +105,6 @@ to open after any grep invocation:
 
     autocmd QuickFixCmdPost *grep* cwindow
 
-## Contributing
-
-Before reporting a bug, you should try stripping down your Vim
-configuration and removing other plugins.  The sad nature of VimScript
-is that it is fraught with incompatibilities waiting to happen.  I'm
-happy to work around them where I can, but it's up to you to isolate
-the conflict.
-
-If your [commit message sucks](http://stopwritingramblingcommitmessages.com/),
-I'm not going to accept your pull request.  I've explained very politely
-dozens of times that
-[my general guidelines](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
-are absolute rules on my own repositories, so I may lack the energy to
-explain it to you yet another time.  And please, if I ask you to change
-something, `git commit --amend`.
-
-Beyond that, don't be shy about asking before patching.  What takes you
-hours might take me minutes simply because I have both domain knowledge
-and a perverse knowledge of VimScript so vast that many would consider
-it a symptom of mental illness.  On the flip side, some ideas I'll
-reject no matter how good the implementation is.  "Send a patch" is an
-edge case answer in my book.
-
 ## Self-Promotion
 
 Like fugitive.vim? Follow the repository on