add text editor options (font size, on/off suggestions)

[geh]

A few options to improve the experience of using rgbds-live:

• specify font size; could be on-screen buttons, a field in the "settings" menu and/or keyboard shortcuts (currently the only way to make font size bigger is to live edit the stylesheet in the web browser)
• disable suggestions/autocomplete ; it is good at the beginning but then it is not needed and makes the interface feel slow

Thanks!

[nummacway]

While you can adjust font size with ctrl+mouse like in any other software in the world, I do think that some autocomplete can be annoying af. Having A as the last argument like in ld b, a is very common and always brings up the autocomplete whose suggestion you will accept if you press enter. Many editors solve this by defining a minimum autocomplete length. 2 would make sense here. But maybe that's just a way to push people into writing comments for every line?