3.0.0-pre.1+1.20.1: 3.0.0-pre.1

- Added option to see grave contents by using an grave compass
- Added new builtin grave styles!
  - `corpse_player` - player (protected) / skeleton (unprotected) lying on the ground.
  - `corpse_zombie` - zombie (protected) / skeleton (unprotected) lying on the ground.
  - `soul` - floating player head (protected) / skull (unprotected) with soul flame particles
- Example models are now written to `config/universal_graves/example_models`
  and need to be copied by hand before modifying. That folder is always recreated.
  Additionally these models are always loaded from Universal Graves itself.
- Changed model format to allow tags requirement per line. With this made default text
  hide breaking/protection values depending on config.
- Improved internal implementation of models.
- Added support of using any entity (including player) and particles as model parts.