CONTRIBUTING.md: Note that new features should be documented (#363)
CONTRIBUTING.md: Note that new features should be documented (#363)

See https://github.com/OctoLinker/browser-extension/pull/362#issuecomment-304760592
josephfrazier/browser-extension,OctoLinker/browser-extension,OctoLinker/browser-extension,josephfrazier/browser-extension,OctoLinker/browser-extension,josephfrazier/browser-extension