Updates to RELEASE.md based on review feedback.
Updates to RELEASE.md based on review feedback.

Signed-off-by: Callum Styan <106b387c595dcc1a235f6eff749ea0675b25b42d@gmail.com>

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