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>

plugins/compounding-engineering/README.md

@@ -67,14 +67,14 @@ Agents are organized into categories for easier discovery.
 
 ### Workflow Commands
 
-Access via `/workflows:command`:
+Core workflow commands (use the short form for autocomplete):
 
 | Command | Description |
 |---------|-------------|
-| `/workflows:plan` | Create implementation plans |
-| `/workflows:review` | Run comprehensive code reviews |
-| `/workflows:work` | Execute work items systematically |
-| `/workflows:codify` | Document solved problems for knowledge base |
+| `/plan` | Create implementation plans |
+| `/review` | Run comprehensive code reviews |
+| `/work` | Execute work items systematically |
+| `/codify` | Document solved problems for knowledge base |
 
 ### Utility Commands