chore: change Gitter to Discord throughout project. (#1507)

* chore: change Gitter to Discord throughout project.
Co-authored-by: 沈唁 <52o@qq52o.cn>

.github/ISSUE_TEMPLATE/bug_report.md

@@ -7,7 +7,7 @@ about: Create a report to help us improve
 <!-- Please use English language -->
 <!-- Before creating an issue please make sure you are using the latest version of Docsify. -->
 <!-- Please ask questions on StackOverflow: https://stackoverflow.com/questions/ask?tags=docsify -->
-<!-- Please ask questions on gitter: https://gitter.im/docsifyjs/Lobby -->
+<!-- Please ask questions on Discord: https://discord.gg/3NwKFyR -->
 
 ## Bug Report
 

README.md

@@ -17,7 +17,7 @@
   <a><img src="https://github.com/docsifyjs/docsify/workflows/Testing%20the%20e2e%20test%20suites/badge.svg?branch=develop&amp;event=push" alt="Testing the e2e test suites"></a>
   <a href="https://www.npmjs.com/package/docsify"><img alt="npm" src="https://img.shields.io/npm/v/docsify.svg?style=flat-square"></a>
   <a href="https://github.com/QingWei-Li/donate"><img alt="donate" src="https://img.shields.io/badge/%24-donate-ff69b4.svg?style=flat-square"></a>
-  <a href="https://gitter.im/docsifyjs/Lobby?utm_source=share-link&utm_medium=link&utm_campaign=share-link"><img alt="gitter" src="https://img.shields.io/gitter/room/docsifyjs/docsify.svg?style=flat-square"></a>
+  <a href="https://discord.gg/3NwKFyR"><img alt="Join Discord community and chat about Docsify" src="https://img.shields.io/discord/713647066802421792.svg?label=&logo=discord&logoColor=ffffff&color=7389D8&labelColor=6A7EC2&cacheSeconds=60"></a>
   <a href="https://gitpod.io/#https://github.com/docsifyjs/docsify"><img src="https://img.shields.io/badge/Gitpod-ready--to--code-blue?logo=gitpod" alt="Gitpod Ready-to-Code"></a>
 </p>
 
@@ -36,7 +36,7 @@
 - [CLI](https://github.com/docsifyjs/docsify-cli)
 - CDN: [UNPKG](https://unpkg.com/docsify/) | [jsDelivr](https://cdn.jsdelivr.net/npm/docsify/) | [cdnjs](https://cdnjs.com/libraries/docsify)
 - [Awesome docsify](https://github.com/docsifyjs/awesome-docsify)
-- [Community chat](https://gitter.im/docsifyjs/Lobby)
+- [Community chat](https://discord.gg/3NwKFyR)
 
 ## Features
 

docs/README.md

@@ -29,7 +29,7 @@ Please consider donating if you think docsify is helpful to you or that my work
 
 ## Community
 
-Users and the development team are usually in the [Gitter chat room](https://gitter.im/docsifyjs/Lobby).
+Users and the development team are usually in the [Discord server](https://discord.gg/3NwKFyR).
 
 ## Special Thanks
 

docs/index.html

@@ -219,13 +219,8 @@
 
         // Public site only
         if (/docsify/.test(location.host)) {
-          ((window.gitter = {}).chat = {}).options = {
-            room: 'docsifyjs/Lobby',
-          };
-
           loadJS('//cdn.jsdelivr.net/npm/docsify@4/lib/plugins/ga.min.js');
           loadJS('//cdn.jsdelivr.net/npm/docsify@4/lib/plugins/matomo.min.js');
-          loadJS('//sidecar.gitter.im/dist/sidecar.v1.js', 'async defer');
         }
       })();
     </script>