docs: update MDN links

Author: sylingd

docs/docs/en-US/guide/custom-function.md

@@ -113,7 +113,7 @@ This parameter is Object and is a read-only parameter. The structure is as follo
 }
 ```
 
-Available resource type see [here](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/webRequest/ResourceType)
+Available resource type see [here](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/ResourceType)
 
 You can use this to implement some advanced features, for example, the following code will only redirect images and videos from example.com to example.org:
 

docs/docs/zh-CN/guide/custom-function.md

@@ -111,7 +111,7 @@ val.push({"name": "test", "value": value.toString()}); //合法
 }
 ```
 
-可用资源类型见[此处](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/webRequest/ResourceType)
+可用资源类型见[此处](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/ResourceType)
 
 您可以借此实现一些高级功能，例如，下面的代码只会将example.com域名下的图片和视频重定向到example.org：
 

docs/docs/zh-TW/guide/custom-function.md

@@ -98,7 +98,7 @@ val.push({"name": "test", "value": value.toString()}); //合法
 }
 ```
 
-可用類型參見[此处](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/webRequest/ResourceType)
+可用類型參見[此处](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/ResourceType)
 
 您可以借此实现一些高级功能，例如，下面的代码只会将example.com域名下的图片和视频重定向到example.org：