add Helm Charts to Installation docs

[steveburnett]

Description

Add linking page for Presto Helm Charts to the Installation docs.

Motivation and Context

Helm Charts are an active interest topic for deploying Presto. Mentioning Helm Charts as an available option in the Installation documentation improves the visibility of Presto Helm Charts to users of the Presto documentation.

Impact

Documentation.

Test Plan

Local build of documentation, verified that the new page was built, that the link in the new page links correctly to the Presto Helm Chart repo, and that the new page was added to the Installation table of contents.

Screenshots of local doc build:

Contributor checklist

• Please make sure your submission complies with our development, formatting, commit message, and attribution guidelines.
• 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

Please follow release notes guidelines and fill in the release notes below.

== RELEASE NOTES ==

General Changes
* Added Helm Charts to Installation documentation. 

[tdcmeehan]

CC: @@dnskr

[dnskr]

@steveburnett Great idea to add the Helm chart to the documentation!
The PR is a good start to make people aware of its existence and increase the chart adoption.