It's common to optionally prefix commands like 'packadd!' with
'silent!', but that wasn't recognized by these patterns.
This change adds 'silent' support to the 'packadd', 'runtime', and
'colorscheme' command patterns.
closes: #18361
Signed-off-by: Jon Parise <jon@indelible.org>
Signed-off-by: Christian Brabandt <cb@256bit.org>