fix(landing): brand alt on nav logo SVG (chmonitor#3389)

Landing already named the nav mark; docs nav used empty alt. Use
"chmonitor" on the docs logo and lock both with tests.

Closes chmonitor#3387

Co-authored-by: duyet <5009534+duyet@users.noreply.github.com>

fix(landing): brand alt on nav logo SVG (chmonitor#3389)

Landing already named the nav mark; docs nav used empty alt. Use
"chmonitor" on the docs logo and lock both with tests.

Closes chmonitor#3387

Co-authored-by: duyet <5009534+duyet@users.noreply.github.com>