[SPARK-46775][DOCS] Fix formatting of Kinesis docs

### What changes were proposed in this pull request?

- Convert the mixed indentation styles (tabs and spaces) to spaces only.
- Add syntax highlighting to the code blocks.
- Fix a couple of broken links to API docs.

### Why are the changes needed?

This makes the docs a bit easier to read and edit.

### Does this PR introduce _any_ user-facing change?

Yes, it changes the formatting of this documentation.

### How was this patch tested?

I built the docs and manually reviewed them.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#44802 from nchammas/kinesis-docs.

Authored-by: Nicholas Chammas <nicholas.chammas@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>