Merge pull request #7 from mbarlow/feat/git-config-simple

git-config-simple: git gd / git gm aliases

Merge pull request #5 from mbarlow/feat/git-diff

git-aware mode (gdf git), difftool support, untracked files

Merge pull request #3 from mbarlow/add-license

Add MIT license

Merge pull request #2 from mbarlow/ci/tests

Release tooling, Why section, install paths