Show committer name or GitHub username in CommitDetailItem

[smashwilson]

I usually recognize my co-workers/fellow open-sourcerers by their names or by their Github handles. I would prefer to see at least the committer's name in the commit details pane.

Stretch goal: show a card on hover with additional information fetched from Github (inspiration)

cc @roberrossmann from #1870 (comment)

[annthurium]

just merged #1906 so this should be in the next release! Thanks @RobertRossman for the suggestion.

[robertrossmann]

Awesome, thanks for incorporating that idea! You guys & gals are great! ❤️