Update manual_install.md opening for SEO
Search results for download GitLab
have https://docs.gitlab.com/omnibus/manual_install.html
as the first result instead of about.gitlab.com/install/
. Original issue documented in gitlab-com/www-gitlab-com#5095 (closed)
We want people searching for this to land on /install/
and would prefer to see it listed as the first result.
I'd like to include download
in the opening as this page links to /install/
and here's my suggestion. Not sure if this matches tone/style guidelines so please update if needed.