Move Presto on Spark page to Administration and refine details

[dnskr]

Description

Move Presto on Spark page to Administration menu.
Refine documentation by making it more formal.

Motivation and Context

The change makes documentation cleaner, consistent and more formal.

Impact

None

Test Plan

Check that Presto on Spark page in the Administration menu and documentation is formatted correctly.

Before changes:

After changes:

Contributor checklist

• Please make sure your submission complies with our contributing guide, in particular code style and commit standards.
• PR description addresses the issue accurately and concisely. If the change is non-trivial, a GitHub Issue is referenced.
• Documented new properties (with its default value), SQL syntax, functions, or other functionality.
• If release notes are required, they follow the release notes guidelines.
• Adequate tests were added if applicable.
• CI passed.

Release Notes

== NO RELEASE NOTE ==

[steveburnett]

LGTM! (docs)

Pull branch, local docs build, looks good. Thanks!