Revamp the doc. Add LICENSE file. (DIYgod#580)

1. 参数现在和英文版一样使用 list
2. 全角`，`, `：`改半角`,`, `:`
3. 补全部分遗漏
4. 修改部分格式

Author: HenryQW

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 DIYgod
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

docs/en/joinus/README.md

@@ -20,7 +20,7 @@ We welcome all pull requests. Suggestions and feedback are also welcomed [here](
 
 ### Access the target data source API
 
-Use [axios](https://github.com/axios/axios) to access the target data source API, assign the acquired title, link, description and datetime to ctx.state.data（refer to Data for the list of parameters）, typically it looks like this: [/routes/bilibili/bangumi.js](https://github.com/DIYgod/RSSHub/blob/master/routes/bilibili/bangumi.js)
+Use [axios](https://github.com/axios/axios) to access the target data source API, assign the acquired title, link, description and datetime to ctx.state.data (refer to Data for the list of parameters) , typically it looks like this: [/routes/bilibili/bangumi.js](https://github.com/DIYgod/RSSHub/blob/master/routes/bilibili/bangumi.js)
 
 ### Acquire data from HTML
 
@@ -72,17 +72,17 @@ Reference article:
 
 -   [Create a podcast - Apple](https://help.apple.com/itc/podcasts_connect/?lang=en#/itca5b22233a)
 -   [Podcast best practices - Apple](https://help.apple.com/itc/podcasts_connect/?lang=en#/itc2b3780e76)
--   Itunes podcast XML generator ：https://codepen.io/jon-walstedt/pen/jsIup
--   Feed Validation Service ：https://podba.se/validate/?url=https://rsshub.app/ximalaya/album/299146/
+-   Itunes podcast XML generator : https://codepen.io/jon-walstedt/pen/jsIup
+-   Feed Validation Service : https://podba.se/validate/?url=https://rsshub.app/ximalaya/album/299146/
 
-these datas can make your podcast subscribeable：
+these datas can make your podcast subscribeable:
 
 ```js
 ctx.state.data = {
     title: '', // The feed title
     link: '', // The feed link
     itunes_author: '', // The channel's author, you must fill this data.
-    itunes_category： '',// Channel category
+    itunes_category:  '',// Channel category
     image: '', // Channel's image
     description: '', // The feed description
     item: [