Update Transfer Delay warning to reflect current roadmap/terminology

Presently, this warning reads:

> Transfers between validators are disabled until at least phase 1. Validators will have to wait until phase 2 (around two years) to be able to withdraw to a specific shard.

Recent discussions have indicated that Phase 2 may not even be pursued, and transfers are typically more associated with Phase 1.5 which we're now calling "The Merge" vs. Phase 1 (sharding).