added contribution guidelines

CONTRIBUTING.md

@@ -0,0 +1,32 @@
+# How To Contribute
+
+If you have an interest in contributing to this project, here is some advice for packaging your contribution. Thanks!
+
+## Contributing Bug Reports
+
+Most likely the most common contribution to a library like this will be bug reports.
+
+**All bug reports need to include**:
+
+- the Android OS version on which you are experiencing the problem
+- the code necessary to reproduce the problem (this could be the repo's demo app, or it could be some demo project of yours that you publish)
+- the steps necessary, using that code and that version of Android, to reproduce the problem
+
+## Contributing Feature Requests
+
+If you have an idea for how to make the library better, feel free to file an [issue](https://github.com/commonsguy/cwac-cam2/issues).
+You will have better luck in getting the feature implemented if you can "sell" the library author
+on how this feature will help the library author.
+
+## Contributing Code
+
+This project is not set up to accept much in the way of pull requests or other code contributions, for
+licensing and contractual reasons, not technical ones.
+
+If you send over a pull request, and it is a *de minimis* fix (i.e., there is no other reasonable way to
+affect the change other than how you did it), your pull request may be accepted and merged in directly.
+Otherwise, pull requests or other code samples will be used as inspiration for a fresh implementation,
+rather than used directly.
+
+In general, you should open a bug report or feature request issue
+first, before submitting a pull request.

README.markdown

@@ -196,6 +196,9 @@ and stack traces if you are encountering crashes.
 
 If you have encountered what is clearly a bug, please post an [issue](https://github.com/commonsguy/cwac-merge/issues). Be certain to include complete steps
 for reproducing the issue.
+The [contribution guidelines](CONTRIBUTING.md)
+provide some suggestions for how to create a bug report that will get
+the problem fixed the fastest.
 
 Do not ask for help via Twitter.