Ability to pin important text/notice on top of a channel (similar to 'Freeze top row' function in excel)

Whenever a channel is active and has a lot of messages coming through, some important message; highlighted notes; or an answer to a FAQ may be overlooked and missed.

If we had the ability to pin such message and highlight it on top (similar to excel's 'Freeze top row' function) moderators/owners in a channel can make their messages more noticeable and seen.