[FLINK-32755][docs] Add doc for OLAP quickstart

[xiangyuf]

What is the purpose of the change

Add quick-start docs for Flink OLAP

Brief change log

• added olap_quickstart.md in docs

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• c160e0a Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[xiangyuf]

@FangYongs @KarmaGYZ hi, can u help review this doc?

[xiangyuf]

@flinkbot run azure

[xiangyuf]

Hi @FangYongs @KarmaGYZ @libenchao this is a joint work between @zoudan and me. Pls add this into the commit message if it has passed the review.

[KarmaGYZ]

Hi @FangYongs @KarmaGYZ @libenchao this is a joint work between @zoudan and me. Pls add this into the commit message if it has passed the review.

You can directly add him. Pls take a look https://docs.github.com/en/pull-requests/committing-changes-to-your-project/creating-and-editing-commits/creating-a-commit-with-multiple-authors .

[FangYongs]

Thanks @xiangyuf , LGTM