Merge pull request #5376 from edx/sarina/new-contributor-docs

CONTRIBUTING.rst

docs/en_us/developers/source/process/community-manager.rst

docs/en_us/developers/source/process/contributor.rst

docs/en_us/developers/source/process/core-committer.rst

docs/en_us/developers/source/process/cover-letter.rst

docs/en_us/developers/source/process/index.rst

docs/en_us/developers/source/process/overview.rst

docs/en_us/developers/source/process/pr-process.graffle

...s/developers/source/process/pr-process.graffle/data.plist

...s/developers/source/process/pr-process.graffle/image2.png

docs/en_us/developers/source/process/pr-process.png

docs/en_us/developers/source/process/product-owner.rst