docs: drop brittle step-number chain from multi-repo row

Addresses review feedback on #1123. Replaces "(same Step 0→1a→1b flow,
matching branch names)" with plain-language instruction that doesn't
forward-reference section numbers that could rot under future edits.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

skills/using-git-worktrees/SKILL.md

@@ -168,7 +168,7 @@ Ready to implement <feature-name>
 | Permission error on create | Sandbox fallback, work in place |
 | Tests fail during baseline | Report failures + ask |
 | No package.json/Cargo.toml | Skip dependency install |
-| Plan touches multiple repos | Create a worktree in each repo (same Step 0→1a→1b flow, matching branch names) |
+| Plan touches multiple repos | Create a matching worktree in each repo, same branch name |
 
 ## Common Mistakes