Clarify which GrapheneOS build keys correspond to the keys needed by avbroot

The standard GrapheneOS build process has you generate a bunch of keys: https://grapheneos.org/build#generating-release-signing-keys It would be good if the avbroot documentation could clarify which keys avb.key and ota.key correspond to. Is it avb.pem (after decryption) and releasekey.pk8?