Fix header level

Signed-off-by: Marcel <MTRNord@users.noreply.github.com>

Author: MTRNord

content/blog/2026/05/2026-05-04-twim.md

@@ -300,7 +300,7 @@ A set of Rust library crates for working with the Matrix protocol. Ruma’s appr
 > **OpenTofu Registry:** <https://search.opentofu.org/provider/raspbeguy/matrix>
 > **Contact:** `@raspbeguy:gugod.fr`
 
-## Connectivity-Tester ([website](https://connectivity-tester.mtrnord.blog/))
+### Connectivity-Tester ([website](https://connectivity-tester.mtrnord.blog/))
 
 [MTRNord (they/them)](https://matrix.to/#/@mtrnord:mtrnord.blog) reports