This updates `fmt` to the latest version and moves to just being a copy
of their repo to make updating easier (no editing their cmake / figuring
out which files to minimally include).
The motivation for this is now that we switched to C++ 20, there were a
ton of deprecated function usages that is going away in future compiler
versions. This gets rid of all those warnings.
- lets you split up your `startup.gc` file into two sections
- one that runs on initial startup / reloads
- the other that runs when you listen to a target
- allows for customization of the keybinds added a month or so ago
- removes a useless flag (--startup-cmd) and marks others for
deprecation.
- added another help prompt that lists all the keybinds and what they do
Co-authored-by: water <awaterford111445@gmail.com>