Badges should reference main

Remove discord link as we will likely just support GitHub Discussions
only in the future.

Author: facelessuser

README.md

@@ -61,11 +61,9 @@ https://facelessuser.github.io/wcmatch/
 MIT
 
 
-[github-ci-image]: https://github.com/facelessuser/wcmatch/workflows/build/badge.svg?branch=master&event=push
-[github-ci-link]: https://github.com/facelessuser/wcmatch/actions?query=workflow%3Abuild+branch%3Amaster
-[discord-image]: https://img.shields.io/discord/678289859768745989?logo=discord&logoColor=aaaaaa&color=mediumpurple&labelColor=333333
-[discord-link]:https://discord.gg/TWs8Tgr
-[codecov-image]: https://img.shields.io/codecov/c/github/facelessuser/wcmatch/master.svg?logo=codecov&logoColor=aaaaaa&labelColor=333333
+[github-ci-image]: https://github.com/facelessuser/wcmatch/workflows/build/badge.svg?branch=main&event=push
+[github-ci-link]: https://github.com/facelessuser/wcmatch/actions?query=workflow%3Abuild+branch%3Amain
+[codecov-image]: https://img.shields.io/codecov/c/github/facelessuser/wcmatch/main.svg?logo=codecov&logoColor=aaaaaa&labelColor=333333
 [codecov-link]: https://codecov.io/github/facelessuser/wcmatch
 [pypi-image]: https://img.shields.io/pypi/v/wcmatch.svg?logo=pypi&logoColor=aaaaaa&labelColor=333333
 [pypi-down]: https://img.shields.io/pypi/dm/wcmatch.svg?logo=pypi&logoColor=aaaaaa&labelColor=333333