Remove contributing guidelines

We already have better guidelines in the wiki, and it is better
kept relevant there than included with releases.

CONTRIBUTING.md

@@ -1,42 +0,0 @@
-How to contribute to noVNC
-==========================
-
-We accept code via pull requests on GitHub.  There are several guidelines that
-we expect contributors submitting code requests to follow.  If you have issues
-following any of these guidelines, feel free to drop us a line by leaving a
-comment in the code request or sending us an email.
-
-Contributing Guidelines
------------------------
-
-* While we don't have an official coding style guide, please try to follow
-  the general coding style of the existing code.
-** Use four spaces instead of tabs 
-** prefix private variables and functions with an `_`
-
-* Please try to include unit tests for your code.  For instance, if you
-  introduce a new encoding, add a test to `tests/test.rfb.js` under the
-  "Encoding Handlers" section (basically, input a small pattern in your
-  encoding and make sure the pattern gets displayed correctly).  If you
-  fix a bug, try to add a unit test that would have caught that bug
-  (if possible -- some bugs, especially visual ones, are hard to test for).
-
-* Squash your commits down in to a clean commit history.  For instance, there
-  should not be "cleanup" commits where you fix issues in previous commits in
-  the same pull request.  Before you go to commit, use `git rebase -i` to
-  squash these changes into the relevant commits.  For instance, a good commit
-  history might look like "Added support for FOO encoding, Added support for
-  BAR message, Placed Button in UI to Trigger BAR" (where each comma denotes
-  a separate commit).
-
-* Add both a title and description to your commit, if possible.  Place more
-  detail on what you did in the description.
-
-Running the unit tests
-----------------------
-
-We use Karma to run our tests. You can launch karma manually, or simply
-run `npm test`.  The Karma debug page will display the tests in normal
-mocha form, if you need it.
-
-Thanks, and happy coding!