This is a common expression and should avoid misunderstanding that `<` and `>` would need to be included

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

Also: move descriptions about difference between the playbook tags (setup-all and install-all) and about the just "recipe" from installing.md to maintenance-upgrading-services.md

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>