New Features
- Added an impossible and obtain item advancement type.
https://github.com/rowan-vr/CustomAdvancements/wiki/Types:-Advancements#impossible-since-v122
https://github.com/rowan-vr/CustomAdvancements/wiki/Types:-Advancements#obtain-item-since-v122

- Added configuration value whether to remove the default minecraft advancement trees, this is true by default.

Bugs Squashed
- Fixed that using shift to craft items only counts as one.
- Fixed wrong example texture in the example advancement tree

Wiki Updated
- Added /ca grantimpossible to the wiki
- Added impossible advancement type to the wiki
- Added obtainitem advancement type to the wiki
- Fixed wrong example values for background texture of an advancement tree