docs(ghc): IDT-884 add documentation for Golden Helm Chart

[BaturaySoysal-TomTom]

Pull Request Description

This PR adds the user documentation for Golden Helm Chart.

Changes Made

• Add Golden Helm Chart documentation.

Why?

This is requested by Golden Helm Chart users and CRA team.

Related Jira Issue(s)

• IDT-884

Type of change

• Documentation content changes

[DavidBaumgold-TomTom]

I'm not sure who is the expected audience of this documentation. Do we assume that they are familiar with Helm and Helm Charts, or not? If they are following the "golden path", they may not be familiar with the tools and are just trying to use the defaults as much as possible; if so, we should make sure that this README explains some of the underlying concepts behind Helm Charts, so the reader has a better chance to know what they are doing. On the other hand, if the intended audience should already know about Helm and Helm Charts, then we can probably remove some unnecessary detail and make these docs more streamlined.

[BaturaySoysal-TomTom]

Some additional feedback I received from @AdrianSzwajkowski-TomTom:

• We should add some working examples for different use cases. This would speed up the onboarding process for first-time users.
• (As also suggested by David) We should provide some additional information/links for people who are not familiar with Helm, ESO, etc.