Smart Villagers Follow Emeralds
A simple Fabric mod that makes villagers follow players holding emerald-related items including Emeralds, Emerald Blocks, Emerald Ore, and Emerald Deepslate Ore.
Doesn't this already exist?
This mod is indeed functionally similar to Villagers-Follow-Emeralds-Fabric, but distinct in a few important ways.
Internally, the comparable Villagers-Follow-Emeralds-Fabric adds an AI goal to villagers to modify their behaviour, which creates a conflict with the brain tasks villagers make use of since 1.14, resulting in often inconsistent emerald following. This mod instead makes use of a proper brain task to add following behaviour, which is much more reliable and future-proof. This is also where the "Smart" in the name comes from.
Another difference is that this mod uses a tag to determine which items tempt villagers, which means that it is possible for server owners and modpack creators to add custom items to this list if they so desire.