docs: use vanity URL for Discord

.github/ISSUE_TEMPLATE.md

@@ -23,7 +23,7 @@ Thanks for your interest in the project. We appreciate bugs filed and PRs submit
   instead of filing an issue on GitHub. You can follow the instructions in this
   codesandbox to make a reproduction of your issue: https://kcd.im/rtl-help
   * Discord
-    https://discord.gg/c6JN9fM
+    https://discord.gg/testing-library
   * Stack Overflow
     https://stackoverflow.com/questions/tagged/react-testing-library
 
@@ -61,6 +61,7 @@ for the supported version.
 Relevant code or config
 
 ```javascript
+
 ```
 
 What you did:

.github/ISSUE_TEMPLATE/Question.md

@@ -16,7 +16,7 @@ For questions related to using the library, please visit a support community
 instead of filing an issue on GitHub. You can follow the instructions in this
 codesandbox to make a reproduction of your issue: https://kcd.im/rtl-help
 
-- Discord https://discord.gg/c6JN9fM
+- Discord https://discord.gg/testing-library
 - Stack Overflow
   https://stackoverflow.com/questions/tagged/react-testing-library
 - Documentation: https://github.com/testing-library/testing-library-docs

README.md

@@ -653,7 +653,7 @@ Contributions of any kind welcome!
 [requests]: https://github.com/testing-library/react-testing-library/issues?q=is%3Aissue+sort%3Areactions-%2B1-desc+label%3Aenhancement+is%3Aopen
 [good-first-issue]: https://github.com/testing-library/react-testing-library/issues?utf8=✓&q=is%3Aissue+is%3Aopen+sort%3Areactions-%2B1-desc+label%3A"good+first+issue"+
 [discord-badge]: https://img.shields.io/discord/723559267868737556.svg?color=7389D8&labelColor=6A7EC2&logo=discord&logoColor=ffffff&style=flat-square
-[discord]: https://discord.gg/c6JN9fM
+[discord]: https://discord.gg/testing-library
 [stackoverflow]: https://stackoverflow.com/questions/tagged/react-testing-library
 [react-hooks-testing-library]: https://github.com/testing-library/react-hooks-testing-library