Hello Balaur

The first commit. A game is a tree of nodes with scripts attached, scenes are TOML files, scripts hot reload, and every subsystem is a plugin.

• A game is a tree of nodes with scripts attached. Under the tree every node is an entity, and physics, rendering, audio, input and UI are plugin systems.
• A scene file declares its nodes in TOML. Plugins add their own keys: body and collider come from the physics crate.
• Saving a script swaps its code into the running game in milliseconds.
• balaur edit runs an editor written in the engine's own scripts.
• balaur export precompiles scripts into a .bpak, and balaur play runs from the bytecode.
• Without the window feature everything runs headless: tests, servers, CI.

[[nodes]]
name = "Ball"
position = [0.0, 6.0, 0.0]
script = { source = "scripts/ball" }
body = "dynamic"                                # from balaur_physics
collider = { shape = "ball", radius = 0.5 }     # from balaur_physics