CONTRIBUTING: Update for Pycopy.
When reporting an issue and especially submitting a pull request, please
make sure that you are acquainted with Contributor Guidelines:
-https://github.com/micropython/micropython/wiki/ContributorGuidelines
+https://github.com/pfalcon/pycopy/wiki/ContributorGuidelines
as well as the Code Conventions, which includes details of how to commit:
-https://github.com/micropython/micropython/blob/master/CODECONVENTIONS.md
+https://github.com/pfalcon/pycopy/blob/master/CODECONVENTIONS.md
