Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,9 +1,15 @@
 # How to contribute
 
-I like to encourage you to contribute to the repository.
+We would like to encourage you to contribute to the repository.
 This should be as easy as possible for you but there are a few things to consider when contributing.
 The following guidelines for contribution should be followed if you want to submit a pull request.
 
+## General rules
+
+* We will mostly only accept bug fixes, and feature expansions rather than completely new features.  However, if you do have a completely new feature that you would like us to consider for inclusion, please submit an issue first.
+* We will almost never accept completely new projects, setting up a new project is complex due to the build processes involved in interlinked NuGets.  Again please submit an issue for discussion first!
+* We will generally aim to support the latest version of .NET and it's associated tooling.
+
 ## How to prepare
 
 * You need a [GitHub account](https://github.com/signup/free)
@@ -40,4 +46,4 @@ _Notice: You can [turn your previously filed issues into a pull-request here](ht
 
 * [General GitHub documentation](http://help.github.com/)
 * [GitHub pull request documentation](http://help.github.com/send-pull-requests/)
-* [Read the Issue Guidelines by @necolas](https://github.com/necolas/issue-guidelines/blob/master/CONTRIBUTING.md) for more details
+* [Read the Issue Guidelines by @necolas](https://github.com/necolas/issue-guidelines/blob/master/CONTRIBUTING.md) for more details