docs: update slash command prefix in skill README

Update `/bd-create` and `/bd-ready` to `/beads:create` and `/beads:ready`
in the claude-code-skill README. This was missed in PR #467.

Relates to #463

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

examples/claude-code-skill/README.md

@@ -119,7 +119,7 @@ Show me what's ready to work on in bd
 
 This skill complements the [beads plugin](../../.claude-plugin/):
 
-- **Plugin** (`.claude-plugin/`): Provides slash commands (`/bd-create`, `/bd-ready`) and MCP tools for basic operations
+- **Plugin** (`.claude-plugin/`): Provides slash commands (`/beads:create`, `/beads:ready`) and MCP tools for basic operations
 - **Skill** (this directory): Teaches Claude the patterns, philosophy, and decision-making for effective beads usage
 
 You can use both together for the best experience: