Convert old "note" text to admonitions

Created by: seancolsen

Admonitions are those colored boxes which say "Note" or "Warning" or other things. It was only a couple months ago that we enabled features inserting admonitions our docs books. So we have lots of content which was written before we started using admonitions. The User Guide would look nicer if we converted this old content to use admonitions.

Here's a command which currently finds 58 occurrences of content which could probably be converted to use admonitions.

grep -PIr '^(> )?(\*\*)?((Note)|(NOTE)|(Warning)|(WARNING)|(Caution)|(CAUTION)|(Tip)|(TIP)|(Important)|(IMPORTANT)|(NB)|(N\.B\.))' .

For each of these things, we want to convert markdown like this...

**Note:** CiviCRM rocks!

to markdown like this...

!!! note
    CiviCRM rocks!

Read more about the syntax for admonitions