ref: 347bb2a7a7110e55debd5ebe57ba03bbe315c5ba
dir: /sys/src/cmd/hg/templates/atom/filelog.tmpl/
{header} <id>{urlbase}{url}atom-log/tip/{file|escape}</id> <link rel="self" href="{urlbase}{url}atom-log/tip/{file|urlescape}"/> <title>{repo|escape}: {file|escape} history</title> {latestentry%feedupdated} {entries%changelogentry} </feed>