Add attestation performance explainer to docs

[nflaig]

We should add https://hackmd.io/@dapplion/lodestar_attestation_summary to our docs to make it more discoverable / visible. We could also create a dedicated page about effectiveness and provide instructions on how to debug sub optimal performance, e.g. what metrics to look at in which order, what logs to look at, important timings etc.

Similar to https://lighthouse-blog.sigmaprime.io/attestation-analysis.html

[philknows]

Related to #5961

[emmaglorypraise]

@philknows Are you working on this issue? Can it be assigned to me?

[lolosaisa]

Hello! I'd like to contribute by adding the attestation performance explainer to the documentation, Please let me know if there are specific areas you'd like me to focus on

[Beutife]

Hi! I’d like to work on this issue. Could you please assign me?

[Beutife]

Thanks for assigning me , I’ll start work on this. Plan: port the HackMD attestation summary into the docs under run/validator-management/, expand it with a high-level attestation flow.

[Beutife]

@philknows hi, good morning, i made a PR, kindly help check it out

[Beutife]

Good morning, i made a pr already, help review it , thanks