Because the README.md seem to incomplete

Hmmmm, you just implement things in Tidbits and you done
Make sure to implement correctly

OK lill try later

Oh I forgot about something, put the mixin config in resource folder
Put config name and return it in getMixinConfigs (return as ImmutableList if you only have 1 mixin config, else just load what you need in the list)

Infact I come from 1.7.10 mixin and I try making mixin in 1.12.2 but it seem to be different

Like I don't know where I can consult IEarlyMixinLoader by example

Ah OK I found it it's in the mixinbooter source code

Always consult the library's comments first, I will expand on the README when I have some time though, thank you!