Improve and update documentation

[hielfx]

Motivation

Update documentation with up-to-date flow diagrams and new information.

Acceptance criteria

• [x] Flow diagrams are updated based on the use case
• [x] Update the documentation in the doc repository
• [x] Documentation in the repository
• [x] How to build, test and develop the CLI
• [x] How to configure the CLI

[hielfx]

We should discuss whether to use the repository wiki or that platform to host the documentation