doc(sdk): update getting started tutorial for mgmt track2 preview (Azure#23640)

* doc(sdk): update getting started tutorial for mgmt track2 preview

- clean up the styling and structure to be consistent with other docs of mgmt track2 preview
- replace examples with the ones from resource managers SDK and compute SDK respectively

* address feedback

Co-authored-by: m-nash <prognash@gmail.com>

Author: archerzz