[Doc][KubeRay] Update RayJob doc

[kevin85421]

Why are these changes needed?

Update the documentation for the KubeRay v1.1.0 release. Additionally, this PR adds a new section to demonstrate how the KubeRay operator cleans up computing resources after the Ray job finishes.

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• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
  • I've added any new APIs to the API Reference. For example, if I added a
    method in Tune, I've added it in doc/source/tune/api/ under the
    corresponding .rst file.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
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  • This PR is not tested :(

[architkulkarni]

Nice! Can you add a brief PR description?

[angelinalg]

Nice use of active voice and removing extraneous words like "please"!
I had some additional nits. Let me know if you have questions.

[angelinalg]

One general comment: I find the terms RayJob and Ray job to be confusing. In addition, in the observability docs, we have the convention of capitalize Ray Job to distinguish it from the more common term of job. In this case, capitalizing Ray Job would add to the confusion. At some point, we should think about names that are less similar to reduce confusion for our readers.