Implementation and examples

The API is implemented in server/lib/eggox/scripts/runtime.ex; window validation is in server/lib/eggox/scripts/window_spec.ex. Executable reference examples are checked by the test suite. Responsive rendering is described further in docs/19-responsive-experience-ui.md.

Lua pattern semantics: https://www.lua.org/manual/5.4/manual.html#6.4.1