docs(git): add research reference corpus for git plugin
11 topic files covering the full git surface area needed for skill and
agent authoring: overview, installation, configuration, cli-reference,
commits (Conventional Commits v1.0.0), branching-merging, submodules,
worktrees, gitflow, remotes (push/pull/fetch/force-with-lease), and
history-inspection (bisect, log --format, pickaxe, --diff-filter).
Includes sources.md mapping all 13 source documents.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0147vXtL5sP6vorDdqXGJJU9
Defame1297
e1e85284d1