High-level documentation/diagrams to explain how ES / CQRS are used

[eloquenza]

The document/diagrams should explain how Event Sourcing and Command Query Responsibility Segregation are used exactly and what they enable (code/technical-wise).
For example, this could showcase a sequence diagram on what happens when a user is creating his own account in our system, i.e. which services are interacting together, how does CQRS / ES help here.

Either in some form of an architecture.md [0] or ADRs [1].

[0] https://www.reddit.com/r/programming/comments/le46br/why_you_need_architecturemd/
[1] https://en.wikipedia.org/wiki/Architectural_decision