docs: add available widgets

Author: vvo

README.md

@@ -13,9 +13,11 @@ API is unstable. We welcome any idea.
 - [Dev](#dev)
 - [Test](#test)
 - [Available widgets](#available-widgets)
-  - [searchBox](#searchbox)
-  - [pagination](#pagination)
   - [hits](#hits)
+  - [multipleChoiceList](#multiple-choice-list)
+  - [pagination](#pagination)
+  - [searchBox](#searchbox)
+  - [stats](#stats)
 
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