feat: Add WeChat posting skill and update marketplace.json

.claude-plugin/marketplace.json

@@ -6,7 +6,7 @@
   },
   "metadata": {
     "description": "Skills shared by Baoyu for improving daily work efficiency",
-    "version": "0.2.0"
+    "version": "0.3.0"
   },
   "plugins": [
     {
@@ -18,6 +18,7 @@
         "./skills/gemini-web",
         "./skills/xhs-images",
         "./skills/post-to-x",
+        "./skills/post-to-wechat",
         "./skills/article-illustrator",
         "./skills/cover-image",
         "./skills/slide-deck"