eager option for functional modifiers is undocumented outside migration guide

[elwayman02]

The v4 Migration guide mentions that all function-based modifiers must add { eager: false } to migrate to v4. However, there is no mention of function-based modifiers having an options hash in the README for v3 or v4, making this an undocumented feature. If functional modifiers are expected to pass this option in v4, it should be documented as part of the core API in the README, not just in the migration guide.

[fairnightzz]

I agree with this as well ^

[didoo]

+1 on this, expecially in the context of Typescript (I had to add a @ts-ignore to prevent TS to complain about this extra argument). Should the signature for the modifiers be updated to include this extra option?