consolidate contributing information

This is to help with slic3r/website#3

[skip ci]

Author: andy5995

.github/CONTRIBUTING.md

@@ -1,3 +1,7 @@
+# CONTRIBUTING
+
+## Bug Reports
+
 Did you encounter an issue with using Slic3r? Fear not! This guide will help you to write a good bug report in just a few, simple steps.
 
 There is a good chance that the issue, you have encountered, is already reported. Please check the [list of reported issues](https://github.com/alexrj/Slic3r/issues) before creating a new issue report. If you find an existing issue report, feel free to add further information to that report.
@@ -24,8 +28,27 @@ Please make sure only to include one issue per report. If you encounter multiple
 
 Simon Tatham has written an excellent on article on [How to Report Bugs Effectively](http://www.chiark.greenend.org.uk/~sgtatham/bugs.html) which is well worth reading, although it is not specific to Slic3r.
 
+## Submitting a Patch
+
 Do you want to help fix issues in or add features to Slic3r? That's also very, very welcome :)
 
+Basically you can follow the [GitHub
+flow](https://guides.github.com/introduction/flow/) for submitting
+patches, but please also read below for more specific information about
+contributing to the Slic3r project.
+
+* Development
+	* [Low Effort tasks](https://github.com/slic3r/Slic3r/labels/Low%20Effort): pick one of them!
+	* [Help Wanted tasks](https://github.com/slic3r/Slic3r/labels/help%20wanted): pick one of them!
+	* [More available tasks](https://github.com/slic3r/Slic3r/milestone/32): let's discuss together before you start working on them
+	* Please comment in the related GitHub issue that you are working on it so that other people know.
+* Contribute to the [Manual](http://manual.slic3r.org/)! (see its [GitHub repository](https://github.com/slic3r/Slic3r-Manual))
+* You can also find us in #slic3r on [FreeNode](https://webchat.freenode.net): talk to _Sound_, _LoH_ or the other members of the Slic3r community.
+* Add an [issue](https://github.com/slic3r/Slic3r/issues) to the GitHub tracker if it isn't already present.
+* Update Slic3r's test suite to improve test coverage [Writing Test Cases](https://github.com/slic3r/Slic3r/wiki/Code:-Writing-Test-Cases)
+* Drop Alessandro a line at [email protected].
+* Drop Joseph a line at [email protected]
+
 * A good place to start if you can is to look over the [Pull Request or Bust](https://github.com/alexrj/Slic3r/milestones/Pull%20Request%20or%20Bust) milestone. This contains all of the things (mostly new feature requests) that there isn't time or resources to address at this time. 
      * Things that are probably fixable via scripts (usually marked as such) have the lowest bar to getting something that works, as you don't need to recompile Slic3r to test.
 * If you're starting on an issue, please say something in the related issues thread so that someone else doesn't start working on it too.

README.md

@@ -53,19 +53,9 @@ If you want to compile the source yourself follow the instructions on one of the
 
 ### Can I help?
 
-Sure! You can do the following to find things that are available to help with:
-
-* Development
-	* [Low Effort tasks](https://github.com/slic3r/Slic3r/labels/Low%20Effort): pick one of them!
-	* [Help Wanted tasks](https://github.com/slic3r/Slic3r/labels/help%20wanted): pick one of them!
-	* [More available tasks](https://github.com/slic3r/Slic3r/milestone/32): let's discuss together before you start working on them
-	* Please comment in the related GitHub issue that you are working on it so that other people know.
-* Contribute to the [Manual](http://manual.slic3r.org/)! (see its [GitHub repository](https://github.com/slic3r/Slic3r-Manual))
-* You can also find us in #slic3r on [FreeNode](https://webchat.freenode.net): talk to _Sound_, _LoH_ or the other members of the Slic3r community.
-* Add an [issue](https://github.com/slic3r/Slic3r/issues) to the GitHub tracker if it isn't already present.
-* Update Slic3r's test suite to improve test coverage [Writing Test Cases](https://github.com/slic3r/Slic3r/wiki/Code:-Writing-Test-Cases)
-* Drop Alessandro a line at [email protected].
-* Drop Joseph a line at [email protected]
+Sure, but please read the
+[CONTRIBUTING](https://github.com/slic3r/Slic3r/blob/master/.github/CONTRIBUTING.md)
+document first!
 
 ### Directory structure