fix: use templater to substitute values in command string
bytes.format() isn't supported on Python 3. Luckily, our template syntax
is similar so we can reuse it. We need a hack to disable \-escapes as '\'
is a directory separator on Windows.
{header}
<title>{repo|escape}: {file|escape} history</title>
<description>{file|escape} revision history</description>
{entries%filelogentry}
</channel>
</rss>