General Engine Fixes

Thanks everyone for your continued support! :)

I've been silently working on major engine fixes and addressing tech debt so that I can reuse this engine to support my future games. There are major changes to the engine in this update that hopefully make the game run smoother but will be completely unnoticeable to you.

Here's a glimpse of what's happened:

• Migrated some parts to new sound library.
• Rewrote intro sequence from CSS animation to Javascript. Can now be paused.
• Fix audio not playing on mobile.
• Translation fixes for Czech language.
• Optimized rendering for certain React components.
• Add cheat menu / console variables.