chore: prettier markdown files

docs/markdown/theme.en-US.md

@@ -21,7 +21,6 @@ There are some basic variables below, all available variables could be found in
 
 ## How to custom theme
 
-
 ### Step 1: import less file
 
 First you should import the less source file to your project. you can use babel-plugin-import to automatically import or just manually import less file.
@@ -39,11 +38,11 @@ module.exports = {
         libraryName: 'vant',
         libraryDirectory: 'es',
         // specify less file path
-        style: name => `${name}/style/less`
+        style: (name) => `${name}/style/less`,
       },
-      'vant'
-    ]
-  ]
+      'vant',
+    ],
+  ],
 };
 ```
 
@@ -107,4 +106,3 @@ module.exports = {
   },
 };
 ```
-