The Migration Guide is here.

The when criteria should search for the use of the following packages
io.vertx.axle.*
io.vertx.reactivex.*

Have a separate rule for each package.

Mandatory, 5 SP, take the message from the Migration Guide
have 2 links, the first to https://quarkus.io/guides/vertx#accessing-vert-x and the second to https://github.com/quarkusio/quarkus/wiki/Migration-Guide-1.12#vertx