Updated writeup for OSB quickstart section (opensearch-project#5177)

* Updated writeup for OSB quickstart section.

Signed-off-by: Govind Kamat <[email protected]>

* Update quickstart.md

Signed-off-by: Naarcha-AWS <[email protected]>

* Update quickstart.md

Signed-off-by: Naarcha-AWS <[email protected]>

* Apply suggestions from code review

Signed-off-by: Naarcha-AWS <[email protected]>

* Apply suggestions from code review

Signed-off-by: Naarcha-AWS <[email protected]>

* Apply suggestions from code review

Signed-off-by: Naarcha-AWS <[email protected]>

* Update _benchmark/quickstart.md

Signed-off-by: Naarcha-AWS <[email protected]>

* Apply suggestions from code review

Signed-off-by: Naarcha-AWS <[email protected]>

---------

Signed-off-by: Govind Kamat <[email protected]>
Signed-off-by: Naarcha-AWS <[email protected]>
Co-authored-by: Naarcha-AWS <[email protected]>