Document how Geo cursor works

Merged Gabriel Mazetto requested to merge 3145-document-how-geo-cursor-works into master

What does this MR do?

Updates Geo documentation and adds additional explanation on our architecture.

Are there points in the code the reviewer needs to double check?

Please double check grammar.

Does this MR meet the acceptance criteria?

What are the relevant issue numbers?

Closes #3145 (closed)

cc @stanhu @dbalexandre @nick.thomas @jarv

Edited by Gabriel Mazetto