docs: update README.md (#701)

Author: 38elements

Diff for: docs/README.md

@@ -47,9 +47,12 @@ Vue Test Utils is the official unit testing utility library for Vue.js.
     * [isVueInstance](api/wrapper/isVueInstance.md)
     * [name](api/wrapper/name.md)
     * [props](api/wrapper/props.md)
+    * [setChecked](api/wrapper/setChecked.md)
     * [setData](api/wrapper/setData.md)
     * [setMethods](api/wrapper/setMethods.md)
     * [setProps](api/wrapper/setProps.md)
+    * [setSelected](api/wrapper/setSelected.md)
+    * [setValue](api/wrapper/setValue.md)
     * [text](api/wrapper/text.md)
     * [trigger](api/wrapper/trigger.md)
     * [isVisible](api/wrapper/isVisible.md)