[SPARK-58520][SQL] Document dynamic table options in SQL reference

[marcuslin123]

What changes were proposed in this pull request?

Document the WITH (key = value) dynamic table options clause in the SQL reference pages for:

• INSERT TABLE
• MERGE INTO
• SELECT

Each page now includes the clause in its syntax, explains how the options are passed to the data
source connector, and provides an example. The MERGE INTO documentation distinguishes target
write options from source read options.

Why are the changes needed?

Spark supports dynamic table options for these statements, but their SQL reference pages did not
document the syntax. Users therefore had to discover the feature through implementation code or
tests.

Does this PR introduce any user-facing change?

No. This is a documentation-only change for existing SQL functionality.

How was this patch tested?

This is a documentation-only change. The changed files pass git diff --check, and their Markdown
code fences were checked for balance. The full Jekyll build was not run because Bundler 2.4.22 is
not installed in the environment.

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

Generated-by: OpenAI Codex (GPT-5) was used for general coding assistance.

[anuragmantri]

@peter-toth - This is PR that adds options syntax to existing DMLs in docs.. Please take a look.

[szehon-ho]

nit: can we put it towards the end ? Its more a speciality so I feel shouldn't be the first one.

[szehon-ho]

same