Revise contribution section and update contact info

Updated contribution guidelines and contact information.

Author: GeeDook

README.md

@@ -91,7 +91,7 @@ This script verifies whether the mirrors defined in `mirrors_list.yaml` are actu
 
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-## How to Contributing to Mirava
+## How to Contribute to Mirava
 
 If you know a reliable mirror (especially one located inside Iran and accessible without a VPN), we’d love to include it.