docs: fix workflow command documentation to use correct syntax

Update all documentation to show the correct command syntax:
- `/plan`, `/review`, `/work`, `/codify` (short form, autocompletes)

Previously showed `/workflows:plan` etc. which doesn't work.
The `name:` field in frontmatter determines the short command name.

Fixes #19

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

docs/pages/changelog.html

@@ -323,7 +323,7 @@
               <li><code>/prime</code> - Prime/setup command</li>
               <li><code>/create-agent-skill</code> - Create or edit Claude Code skills</li>
               <li><code>/heal-skill</code> - Fix skill documentation issues</li>
-              <li><code>/workflows:codify</code> - Document solved problems for knowledge base</li>
+              <li><code>/codify</code> - Document solved problems for knowledge base</li>
             </ul>
 
             <h4>New Skills (10)</h4>