contributing.rst: added some more relevant information

Included IRC channels, and some relevant AOSP build related
information.

Change-Id: I5455bc30f63e0fdac65d6da6ac98c27147d401d0
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
1 file changed
tree: 51f2452c0721f6b32f8fae6ad0c334730535bcc7
  1. docs/
  2. .gitignore
  3. .readthedocs.yaml