Update eth-secpm.md

[ramsesfv]

Added flow diagrams

[rymnc]

I think these images are meant to be uploaded to the rfc-index, can you do that? and reference them this way?
context:
waku-rln-relay rfc-index: https://github.com/vacp2p/rfc-index/blob/69f28534075d1486ebff0f292cd4e2fa80f6fd1b/waku/standards/core/17/rln-relay.md?plain=1#L62C1-L62C51
and the images go in the spec/images directory
https://github.com/vacp2p/rfc-index/tree/main/waku/standards/core/17/images

[rymnc]

Based on the flow diagrams, it is still not clear what the authentication service should actually return. maybe i am missing something, but more context would be helpful here, thanks!

[kaiserd]

Could we merge this as an other intermediate step and open a new PR?
Just to keep the version on the index more up to date?
Wdyt @rymnc
cc @jimstir

[rymnc]

@ramsesfv please update the branch and merge :)