Perform a first round of audit

[ch1bo]

Why

We want to get the Hydra code base audited by internal & external auditors to ensure increase the maturity of the codebase and our confidence in using it ultimately on mainnet.

What

This item is about performing a first audit round with a team at IOG to find a first round of issues & verify whether our documentation / specification is suitable for consumption (related to #448)

How

• [ ] Create an architecture page and also document the behavior of the hydra-node ("from the outside"), e.g. as part of the api reference
• [ ] Static analysis of the code
  • [ ] ...
• [ ] Dynamic analysis of the code
• [ ] ...