Saving and Quality of Life improvements

You can finally save your game so that you can create much more massive factories, and you never have to worry about starting from scratch again. The interaction control wasn't very well suited for playing in the browser so it has been changed by default (to 'E'), and you can change every keybind in the game now.

With the ability to save, it looks like more content might be needed to allow for more complex factories...

---Full Patch Notes---

-- Saving/Loading. This currently only has one slot so make sure only to save your most important factory! This will be expanded upon in the future.

-- Options Menu. This is where you will be able to find all of the game's keybindings, as well as change them to whatever you like. There's also volume sliders in this page so that you can set everything's volume just right.

-- Default keybind for 'interaction' has been changed from 'mouse2' to 'E'

-- Your cursor will now turn red when you are holding the button to destroy tiles. This was hard to notice before.