ESM Script docs

[marklundin]

We need to add relevant documentation for using ESM Script as features rolls out. A non-exhaustative list;

• [x] General Class based syntax
• [x] Attributes Definitions
• [x] import /exporting including path mapping
• [x] Caveats/Limitations
  • [x] Dynamic Import Expressions
  • [x] Attribute Getters/Setters
• [x] Bundling
• [x] ESM Examples - Update examples/tutorials with pc.createScript syntax to show ESM equivalent. This can be shown as a docusaurus Tab, with some persistent state that applies site wide. https://github.com/playcanvas/developer.playcanvas.com/pull/644

[marklundin]

This has been completed here https://github.com/playcanvas/developer.playcanvas.com/tree/esm-script-examples. Awaiting approval