Update Vanilla Registry Documentation

[WaitingIdly]

changes in this PR:

• update documentation of vanilla registries to be generated via Document Vanilla Registries GroovyScript#300.
  • new: command, gameRule.
  • updated: crafting, furnace, oreDict, player, rarity.
    • crafting now indicates that it can be removed by ResourceLocation.
  • rename the index from Helpers to Registries to hopefully make it more visible.
  • minor adjustments made to ensure correctness due to lacking generation based on global bindings for aliases.
• update documentation for atum, aether legacy, pyrotech, and industrial foregoing to match the new ForgeRegistryWrapper doc annotations.
• add a number file names to different codeblocks.
• improve wording in groovy_modifications.md.
• fix incorrect code examples in differences_from_java.md, where the java code was incorrect. also update the map example to highlight more alternatives.
• add a handful of ways to count loops in loops.md
• add a warning to maps.md relating to the key being a method requiring being wrapped in parentheses to function properly.

i was rather surprised that some of these changes were in here, as i had meant to open a separate PR for them. simply forgot to switch branches.