A more accurate verification explanation

[themighty1]

Currently in https://github.com/tlsnotary/docs-mdbook/blob/main/src/protocol/verification.md
one of the steps is that the Prover provides
Session Header signed by the Verifier

this should be more accurately reworded along the lines of:
Session Header trusted by the Verifier (i.e. signed by a trusted Notary or created by the Verifier themselves)

However, the latter is also not entirely accurate since if the Verifier created the Session Header and stores it locally, there is no need for the Prover to provide the header during verification.