Consider adding auto-generated indexes

[ItsDrike]

By default minecraft-data provides us with a lot of lists full of entires that are unique in id or name fields, however, if you'd want to get a specific entry with that id, you'd need to walk the whole list.

We could add some auto-generated index entries for these to make accessing such data easier.

This is also what node-minecraft-data is doing: https://github.com/PrismarineJS/node-minecraft-data/blob/master/lib/indexes.js