misleading comment description in verify_proof function

[levs57]

The comment on this line https://github.com/zcash/halo2/blob/5678a506cbec60d593a21ff618d09bed48abf7f2/halo2_proofs/src/plonk/verifier.rs#L66 suggests that the verify_proof function returns a bool value indicating whether a proof is correct or not.

However, this is misleading, in fact, it returns Result<V::Output, Error>, for a verification strategy V, which, is in fact, not boolean.