Rewrite "recursion and max depth" page

[miparnisari]

https://authzed.com/docs/spicedb/modeling/recursion-and-max-depth

some ideas:

• change the title to be clearer? maybe "cyclical relationships"?
• clarify what "max depth" is, and how it relates to the tree (number of nodes that we can "hop" on the tree before returning an error).
  • also why do we even need this section? do people need to set this flag, does it not come with a default??
• clarify how cycles are detected if not by object tracking (https://authzed.com/docs/spicedb/modeling/recursion-and-max-depth#why-doesnt-spicedb-simply-support-tracking-the-objects-it-has-walked)
• nice to have: a drawing of a graph, and a specific path in the graph symbolizing a Check request