Add meaningful titles for callouts

Re: the below comment, at some point in the future callouts should be given more meaningful titles.

Thanks, LGTM. In future we might wish to encourage giving callouts more meaningful titles but that isn't an immediate priority...

_Originally posted by @jo3-l in https://github.com/botlabs-gg/yagpdb-docs-v2/pull/37#pullrequestreview-2120840030_