Add a note about hacking on ghcide from Windows (haskell/ghcide#463)

* Add a note about hacking on ghcide from Windows

See https://github.com/digital-asset/ghcide/pull/435haskell/ghcide#issuecomment-592504569 for context

* Update README.md

Co-Authored-By: Javier Neira  <atreyu.bbb@gmail.com>

Co-authored-by: Javier Neira  <atreyu.bbb@gmail.com>

Author: ndmitchell

ghcide/README.md

@@ -252,6 +252,7 @@ using `stack install ghcide` within a project.
 
 To build and work on `ghcide` itself, you can use Stack or cabal, e.g.,
 running `stack test` will execute the test suite.
+If you are using Windows, you should disable the `auto.crlf` setting and configure your editor to use LF line endings, directly or making it use the existing `.editor-config`.
 
 ### Building the extension