Add link to (unwritten) contributing guide

README.md

 fslpy
 =====
 
+
 The `fslpy` project is a [FSL](http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/)
 programming library written in Python. It is used by
 [FSLeyes](https://git.fmrib.ox.ac.uk/paulmc/fsleyes/).
@@ -27,6 +28,10 @@ running:
 The HTML documentation will be generated and saved in the `doc/html/` directory.
 
 
+If you are interested in contributing to `fslpy`, check out the [contributing
+guide](doc/contributing.rst).
+
+
 Tests
 -----
 

doc/contributing.rst

+Contributing to fslpy
+=====================
+
+TODO
+
+Key points:
+
+ - The master branch should always be stable and ready to release
+
+ - A separate branch is created for each release
+
+ - Development occurs through a pull request (a.k.a. "merge request") model. All
+   changes to the master branch occur via merge requests.
+
+ - Use semantic versioning, to allow for compatibilty testing:
+   http://semver.org/
+
+ - Unit tests are currently run with `py.test` and `coverage`. Aim for 100%
+   code coverage.

doc/index.rst

@@ -11,3 +11,4 @@ by |fsleyes_apidoc|_.
 
    self
    fsl
+   contributing