Local development plan

[LPGhatguy]

Currently, Tarmac supports uploading to Roblox.com only. For fast local iteration, it would be useful for Tarmac to copy your assets into your local Roblox Studio content folder temporarily.

To do that, we could introduce a new value for --target named something like local-studio:

tarmac sync --target local-studio

This command would:

1. Locate your local Roblox Studio install using roblox-install
2. Perform a sync. For any files that have changed, copy them to $INSTALL/content/.tarmac/<hash>.
3. Perform codegen, using a path like rbxasset://.tarmac/<hash> for any assets that have no asset ID.