docs: add links for sync option (#487)

Author: 38elements

docs/en/README.md

@@ -29,6 +29,7 @@ Vue Test Utils is the official unit testing utility library for Vue.js.
     - [attrs](api/options.md#attrs)
     - [listeners](api/options.md#listeners)
     - [provide](api/options.md#provide)
+    - [sync](api/options.md#sync)
     - [other options](api/options.md#other-options)
   * [Wrapper](api/wrapper/README.md)
     * [attributes](api/wrapper/attributes.md)

docs/en/SUMMARY.md

@@ -25,6 +25,7 @@
     - [attrs](api/options.md#attrs)
     - [listeners](api/options.md#listeners)
     - [provide](api/options.md#provide)
+    - [sync](api/options.md#sync)
     - [other options](api/options.md#other-options)
   * [Wrapper](api/wrapper/README.md)
     * [attributes](api/wrapper/attributes.md)

docs/en/api/README.md

@@ -13,6 +13,7 @@
   - [attrs](./options.md#attrs)
   - [listeners](./options.md#listeners)
   - [provide](./options.md#provide)
+  - [sync](./options.md#sync)
   - [other options](./options.md#other-options)
 * [Wrapper](./wrapper/README.md)
   * [attributes](./wrapper/attributes.md)

docs/en/api/options.md

@@ -172,7 +172,8 @@ Pass properties for components to use in injection. See [provide/inject](https:/
 - type: `boolean`
 - default: `true`
 
-Sets all watchers to run synchronously. 
+When `sync` is `true`, the Vue component is rendered synchronously.  
+When `sync` is `false`, the Vue component is rendered asynchronously.
 
 ## Other options