docs: misc extra protocol circuit comments

[iAmMichaelConnor]

Found some useful comments on a local branch :)

[AztecBot]

Flakey Tests

🤖 says: This CI run detected 3 tests that failed, but were tolerated due to a .test_patterns.yml entry.

\033FLAKED\033 (\0338;;http://ci.aztec-labs.com/4a50b6ae28c6a324�4a50b6ae28c6a3248;;�\033):  yarn-project/end-to-end/scripts/run_test.sh simple src/e2e_p2p/multiple_validators_sentinel.parallel.test.ts "collects attestations for validators in proposer node when block is not published" (108s) (code: 1) group:e2e-p2p-epoch-flakes (\033iAmMichaelConnor\033: doc: misc extra protocol circuit comments)
\033FLAKED\033 (\0338;;http://ci.aztec-labs.com/fb2286fd3d38bf72�fb2286fd3d38bf728;;�\033): LOG_LEVEL=debug yarn-project/scripts/run_test.sh p2p/src/client/p2p_client.test.ts (83s) (code: 1) group:e2e-p2p-epoch-flakes (\033iAmMichaelConnor\033: doc: misc extra protocol circuit comments)
\033FLAKED\033 (\0338;;http://ci.aztec-labs.com/6c39f7aab1857d40�6c39f7aab1857d408;;�\033): yarn-project/scripts/run_test.sh p2p/src/mem_pools/tx_pool/aztec_kv_tx_pool.test.ts (573s) (code: 134) group:e2e-p2p-epoch-flakes (\033iAmMichaelConnor\033: doc: misc extra protocol circuit comments)