cluster classification diagrams

[gianlucam76]

User Story

As a developer I would like comprehensive documentation of the cluster classification flow.
For instance, when Classifier instance is created, it gets deployed in the managed clusters. And if classifier-agent is not already present, agent gets also deployed.
How the agent reacts to events (cluster upgrades, resources created/deleted) and how clusters match are reported back to management cluster and processed there.

Detailed Description

In order to make it easier for devs to quickly understand sveltos internals, in the documentation (https://projectsveltos.github.io/sveltos/) create a developer section with diagrams of above flow.

/kind documentation
/help
/good-first-issue