Add Chinese documentation for custom skills development and reference guide

- Created a new document for custom skills development (`custom.md`) detailing the structure, creation, implementation, and best practices for developing custom CCW skills.
- Added an index document (`index.md`) summarizing all built-in skills, their categories, and usage examples.
- Introduced a reference guide (`reference.md`) providing a quick reference for all 33 built-in CCW skills, including triggers and purposes.

docs/.vitepress/theme/components/AgentOrchestration.vue

@@ -264,7 +264,7 @@ function hideTooltip() {
   }
 }
 
-@media (max-width: 640px) {
+@media (max-width: 768px) {
   .agent-orchestration {
     padding: 2rem 1rem;
   }