Replace Discourse with Github Discussions (#13322)

fixed #13321

README.md

@@ -8,7 +8,6 @@
 <div id="badges" align="center">
 
   [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-curved)](https://github.com/eclipse-theia/theia/labels/help%20wanted)
-  [![Discourse status](https://img.shields.io/discourse/status?label=Chat&server=https%3A%2F%2Fcommunity.theia-ide.org%2F)](https://community.theia-ide.org/)
   [![Build Status](https://github.com/eclipse-theia/theia/workflows/Build/badge.svg?branch=master)](https://github.com/eclipse-theia/theia/actions?query=branch%3Amaster+event%3Apush+event%3Aschedule)
   [![Publish VS Code Built-in Extensions](https://github.com/eclipse-theia/vscode-builtin-extensions/actions/workflows/publish-vsx-latest.yml/badge.svg?branch=master)](https://github.com/eclipse-theia/vscode-builtin-extensions/actions/workflows/publish-vsx-latest.yml)
   [![Open questions](https://img.shields.io/badge/Open-questions-blue.svg?style=flat-curved)](https://github.com/eclipse-theia/theia/discussions/categories/q-a)
@@ -88,7 +87,7 @@ Read below to learn how to take part in improving Theia:
 
 Read below how to engage with Theia community:
 
-- Join the discussion on [Discourse](https://community.theia-ide.org/).
+- Join the discussion on [GitHub](https://github.com/eclipse-theia/theia/discussions).
 - Ask a question, request a new feature and file a bug with [GitHub issues](https://github.com/eclipse-theia/theia/issues/new/choose).
 - Vote on existing GitHub issues by reacting with a 👍. We regularly check issues with votes!
 - Star the repository to show your support.

doc/Publishing.md

@@ -40,7 +40,7 @@ In order to successfully perform a `yarn upgrade` one must:
 ### Announce Release
 
 It is a good idea to give a heads-up to developers and the community some hours before a release.
-At the time of writing this is [Discourse](https://community.theia-ide.org/). Here is an [example](https://community.theia-ide.org/t/eclipse-theia-v1-40-0-release/3112/5).
+At the time of writing this is [GitHub Discussions](https://github.com/eclipse-theia/theia/discussions). Here is an [example](https://github.com/eclipse-theia/theia/discussions/13314).
 
 ### Localization