Add NEWS file, cut release

Blocked by: system-transparency/project/documentation!44 (merged)

Use the guidelines and tailor for this repository. Specify the tag as, e.g., v0.14.X at the top of the news file and replace X with the final tag that is getting released right before you're ready to do the final steps (like creating release page entry, shooting email, etc. Ask someone to review your release email.)