readme: update Twitter name and link (#6874)

README.md

@@ -16,7 +16,7 @@
 	<a href="https://github.com/caddyserver/caddy/actions/workflows/ci.yml"><img src="https://github.com/caddyserver/caddy/actions/workflows/ci.yml/badge.svg"></a>
 	<a href="https://pkg.go.dev/github.com/caddyserver/caddy/v2"><img src="https://img.shields.io/badge/godoc-reference-%23007d9c.svg"></a>
 	<br>
-	<a href="https://twitter.com/caddyserver" title="@caddyserver on Twitter"><img src="https://img.shields.io/badge/twitter-@caddyserver-55acee.svg" alt="@caddyserver on Twitter"></a>
+	<a href="https://x.com/caddyserver" title="@caddyserver on Twitter"><img src="https://img.shields.io/twitter/follow/caddyserver" alt="@caddyserver on Twitter"></a>
 	<a href="https://caddy.community" title="Caddy Forum"><img src="https://img.shields.io/badge/community-forum-ff69b4.svg" alt="Caddy Forum"></a>
 	<br>
 	<a href="https://sourcegraph.com/github.com/caddyserver/caddy?badge" title="Caddy on Sourcegraph"><img src="https://sourcegraph.com/github.com/caddyserver/caddy/-/badge.svg" alt="Caddy on Sourcegraph"></a>
@@ -192,8 +192,8 @@ Matthew Holt began developing Caddy in 2014 while studying computer science at B
 
 **The name "Caddy" is trademarked.** The name of the software is "Caddy", not "Caddy Server" or "CaddyServer". Please call it "Caddy" or, if you wish to clarify, "the Caddy web server". Caddy is a registered trademark of Stack Holdings GmbH.
 
-- _Project on Twitter: [@caddyserver](https://twitter.com/caddyserver)_
-- _Author on Twitter: [@mholt6](https://twitter.com/mholt6)_
+- _Project on X: [@caddyserver](https://x.com/caddyserver)_
+- _Author on X: [@mholt6](https://x.com/mholt6)_
 
 Caddy is a project of [ZeroSSL](https://zerossl.com), a Stack Holdings company.