Add RELEASE.md
Add RELEASE.md

Signed-off-by: Frederic Branczyk <be573f521a508b499399d1fa7c86d0d9ce29e56d@gmail.com>

Gouthamve/prometheus,kangwoo/prometheus,alileza/prometheus,alileza/prometheus,alileza/prometheus,keegancsmith/prometheus,kangwoo/prometheus,keegancsmith/prometheus,prometheus/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,prometheus/prometheus,keegancsmith/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,Gouthamve/prometheus,prometheus/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,kangwoo/prometheus,prometheus/prometheus