[Feature] Save bot messages

[qucchia]

Describe the bug The bot's messages aren't saved in history. For example, type the /shrug command and refresh the page, and it will have gone.

Expected behavior The bot's messages should be saved.

[micahlt]

This was originally intentional - do you think this should be implemented?

[icarusinthewings]

I think this would be nice.

[micahlt]

@VelocityDesign The issue with this is that it's unnecessary storage for Heroku to handle. I've got no feasible way of handling a storage overflow at the moment because I have no way of detecting the amount of storage left on Heroku's server. Eventually, as (or rather, if) Modchat grows, I'll have to upgrade to a more dynamic database as in-server DB's aren't a good practice.