Fix tune resources example code (#28210)
Fix tune resources example code (#28210)

The tune resources user guide contained broken code snippets. This PR fixes those, adds some extra clarifying comments, and improves the code style for readability.

Signed-off-by: Justin Yu <61f92b3ff271a8158a70de7ae046dc8d0a8718f6@berkeley.edu>
ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray