Merge branch 'kh/doc-trailers' into kh/trailers-no-urls

* kh/doc-trailers: doc: interpret-trailers: document comment line treatment doc: interpret-trailers: rewrite new-trailers paragraphs doc: interpret-trailers: commit to “trailer block” term doc: interpret-trailers: join new-trailers again doc: interpret-trailers: add key format example doc: interpret-trailers: explain key format doc: interpret-trailers: explain the format after the intro doc: interpret-trailers: not just for commit messages doc: interpret-trailers: use “metadata” in Name as well doc: interpret-trailers: replace “lines” with “metadata” doc: interpret-trailers: stop fixating on RFC 822