chore: use a matrix.to link instead for the matrix room

- use the correct room link
- remove beta badge

Signed-off-by: Brian McGee <brian@bmcgee.ie>

Author: brianmcgee

README.md

@@ -11,8 +11,7 @@ _A <a href="https://numtide.com/">numtide</a> project._
 <p>
 <a href='https://coveralls.io/github/numtide/treefmt?branch=main'><img src='https://coveralls.io/repos/github/numtide/treefmt/badge.svg?branch=main' alt='Coverage Status' /></a>
 <a href="https://github.com/numtide/treefmt/actions/workflows/release.yml"><img src="https://github.com/numtide/treefmt/actions/workflows/release.yml/badge.svg"/></a>
-<img alt="Static Badge" src="https://img.shields.io/badge/status-beta-yellow">
-<a href="https://app.element.io/#/room/#home:numtide.com"><img src="https://img.shields.io/badge/Support-%23numtide-blue"/></a>
+<a href="https://matrix.to/#/#treefmt:numtide.com"><img src="https://img.shields.io/matrix/treefmt:numtide.com?server_fqdn=matrix.org&label=Matrix&logo=matrix"/></a>
 </p>
 
 </div>