Fix maintainer link README.md

[Night-Chan]

Previous maintainer request link was broken, missing one character

Please make sure to check the following tasks before opening and submitting a PR

• [x] I understand and have followed the contribution guide
• [x] I have tested my changes locally and they are working as intended
• [x] These changes do not have any notable side effects on other Revolt projects

[Rexogamer]

Closing as this is an issue with the README template that I will fix in a moment - thanks for spotting it though!