docs: Update release notes (fixes #18)

RELEASES.md

 # Releases
 
-## 2.1.0
+## 2.2.x
 
 - Node.js 16.x support removed.
+- Switch to dnf module (RHEL).
 
-## 2.0.0
+## 2.1.x
+
+- RHEL repositories updates.
+- AL2 upstream releases.
+
+## 2.0.x
 
 - Node.js 20.x set as default version.
 - RedHat 7 and Ubuntu 18.04 support removed.
 - Node.js 18.x and 20.x for Amazon Linux 2 support added.
 
-## 1.0.0
+## 1.0.x
 
 - Ubuntu 22.04 LTS support added.
 - Node.js 16.x