Merge branch 'docs/repo-naming-hyphens'

Adds the repo-naming rule (hyphens, not underscores) next to
trunk naming in Branching.

git-operations.md

@@ -28,6 +28,9 @@ deviation from this default, and belongs in that project's own KB corpus, not he
 else), work with what's there. Never rename a repo's default branch as an incidental part of
 unrelated work.
 
+**Repo name: hyphens, not underscores** (`my-project`, not `my_project`) — for new repos, same
+caveat as trunk naming: don't rename an existing one over this.
+
 **Naming scheme: `type/short-description`.** A type prefix from the taxonomy below, then a
 kebab-case description — `feat/branch-naming-rules`, `fix/null-check-on-login`. No ticket ID in the
 name: a branch name should say what the change does, and if a tracker ticket exists, that reference