docs: some tweaks

Author: ulivz

packages/docs/docs/config/README.md

@@ -179,7 +179,7 @@ Provide config options to the used theme. The options will vary depending on the
 - Type: `Object|Array`
 - Default: `undefined`
 
-Please refer to [plugin API >  Using a plugin](../plugin/README.md#using-a-plugin) to leran how to use a plugin.
+Please refer to [Plugin > Using a plugin](../plugin/README.md#using-a-plugin) to leran how to use a plugin.
 
 ## Markdown
 

packages/docs/docs/theme/README.md

@@ -239,4 +239,4 @@ The plugin whose name starts with `@vuepress/theme-` is an officially maintained
 - Type: `Array|Object`
 - Default: undefined
 
-See: [Config > plugins](../config/README.md#plugins).
+See: [Plugin > Using a plugin](../plugin/README.md#using-a-plugin).

packages/docs/docs/zh/config/README.md

@@ -174,7 +174,7 @@ VuePress provides a convenient way to add extra styles. you can create an `.vuep
 - Type: `Object|Array`
 - Default: `undefined`
 
-请参考 [plugin API >  Using a plugin](../plugin/README.md#using-a-plugin) 来使用一个插件。
+请参考 [plugin > Using a plugin](../plugin/README.md#using-a-plugin) 来使用一个插件。
 
 ## Markdown
 

packages/docs/docs/zh/plugin/README.md

@@ -4,6 +4,8 @@ sidebar: auto
 
 # Plugins
 
+> To be translated soon.
+
 ## Writing a Plugin
 
 Plugins usually add global-level functionality to VuePress. There is no strictly defined scope for a plugin - there are typically several types of plugins:

packages/docs/docs/zh/theme/README.md

@@ -4,6 +4,8 @@ sidebar: auto
 
 # Theme
 
+> To be translated soon.
+
 ::: tip
 Theme components are subject to the same [browser API access restrictions](../guide/using-vue.md#browser-api-access-restrictions).
 :::
@@ -239,4 +241,4 @@ The plugin whose name starts with `@vuepress/theme-` is an officially maintained
 - Type: `Array|Object`
 - Default: undefined
 
-See: [Config > plugins](../config/README.md#plugins).
+See: [Plugin > Using a plugin](../plugin/README.md#using-a-plugin).