This adds extra types that Angular doesn't use. "interface" is for
frontend related changes etc. "i18n" means internationalization and
refers to translations, etc.
Fixes#2622.
This adds a Git commit-msg hook which runs after a commit message is
written. It verifies that is matches a certain spec as defined by the
AngularJS document here:
https://docs.google.com/document/d/1QrDFcIiPjSLDn3EL15IJygNPiHORgU1_OOAqWjiDU5Y/edit#
This will allow for autmoated generation of Changelog.md in the future.
Migration notes: Please run `ln -sf ../../validate-commit-msg.js
.git/hooks/commit-msg` to install the commit hook.