Add Markdown for Heading

Could you guys maybe add support for headings like in markdown?
So like:

# Heading 1

## Heading 2

### Heading 3

This shouldn't interfere with channel mentions because you always need a space after the hashtags and those have to be at the beginning of the line.

This would make it easier to create rules and other information messages that don't look like a gigantic block of text.

Thank you in advance