Publish json schema files for datapacks

This is very simple: Publish a json schema file for advancements files etc. at some url. This would allow 2 things: 1. Users could put a „$schema“: “the url“ in their IDE and have autocompletion and error checking. This eases the learning curve with map making. 2. Creators that have a lot of advancements ( and recipe files and whatever the bedrock scripting API/Addons is using ) can use command-line tools to automatically check their creations for errors. This can be done in github actions for example. This would increase stability in data packs and by extension contribute to maturing the ecosystem. *Prior Art*: Several github projects are attempting the same thing, but they are not very well maintained.