remove unnecessary comma

sidebars.js

@@ -52,7 +52,7 @@ module.exports = {
           {
             type: 'autogenerated',
             dirName: 'usage',
-          },
+          }
       ]
     },
     {
@@ -129,7 +129,7 @@ module.exports = {
           {
             type: 'autogenerated',
             dirName: 'zh-cn/usage',
-          },
+          }
       ]
     },
     {