Merge branch 'https://github.com/tj/git-extras.wiki/master' into docs

* wiki/master: (30 commits)
  git merge-repo
  add wiki for git-guilt
  Update docs for revised git-changelog.
  add wiki for git-merge-into
  git scp tj#300
  link to git delta
  git delta usage
  Add git-authors
  Updated Commands (markdown)
  Updated Commands (markdown)
  Updated Commands (markdown)
  Updated Commands (markdown)
  Updated Commands (markdown)
  Fix link to git feature command
  Added a footer.
  add a few keywords
  some remaining dashes
  roughly finished
  Updated Commands (markdown)
  Updated Commands (markdown)
  ...