[w3c/manifest] Minor text tweaks (#664)

You can view, comment on, or merge this pull request online at:

  https://github.com/w3c/manifest/pull/664

-- Commit Summary --

  * Minor text tweaks

-- File Changes --

    M CONTRIBUTING.md (2)
    M explainer.md (8)

-- Patch Links --

https://github.com/w3c/manifest/pull/664.patch
https://github.com/w3c/manifest/pull/664.diff

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/manifest/pull/664