chore(FR-2108): add docs-toolkit package to VS Code workspace (#5505)

Author: yomybaby

backend.ai-webui.code-workspace

@@ -16,6 +16,10 @@
       "path": "packages/backend.ai-webui-docs",
       "name": "webui-docs",
     },
+    {
+      "path": "packages/backend.ai-docs-toolkit",
+      "name": "docs-toolkit",
+    },
   ],
   "settings": {
     "i18n-ally.enabledFrameworks": ["react", "custom"],