doc/ContributingCode.md add more links needed at given context
doc/ContributingCode.md add more links needed at given context

Change-Id: I331ac7b24fd35735a0822a6b86ece66e1847f475
Reviewed-on: https://chromium-review.googlesource.com/347130
Reviewed-by: Jamie Madill <7e492b4f1c8458024932de3ba475cbf015424c30@chromium.org>
Reviewed-by: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>
Commit-Queue: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>

MSOpenTech/angle,domokit/waterfall,ppy/angle,ecoal95/angle,ecoal95/angle,domokit/waterfall,ppy/angle,MSOpenTech/angle,ecoal95/angle,MSOpenTech/angle,ecoal95/angle,MSOpenTech/angle,ppy/angle,ppy/angle,ecoal95/angle