Backport of CAPIgw for K8s installation updates for 1.16 into release/1.16.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #17627 to be assessed for backporting due to the inclusion of the label backport/1.16.

🚨

Warning automatic cherry-pick of commits failed. If the first commit failed,
you will see a blank no-op commit below. If at least one commit succeeded, you
will see the cherry-picked commits up to, not including, the commit where
the merge conflict occurred.

The person who merged in the original PR is:
@trujillo-adam
This person should manually cherry-pick the original PR into a new backport PR,
and close this one when the manual backport PR is merged in.

merge conflict error: unable to process merge commit: "688b77abb4f886f6c01f66587a5db75b118bf319", automatic backport requires rebase workflow

The below text is copied from the body of the original PR.

---

Description

This PR removes the additional step of installing CRDs for API gateway on K8s from the documentation.

PR Checklist

• external facing docs updated
• appropriate backport labels added
• not a security concern

---

Overview of commits

• 2cfd6a4 - b7be18d - 688b77a - 01f2ace - 3ec3caf - a581b4e - 7139924 - 45fb074 - 41db724 - d2bb4bc - b299704 - 3fa1a0b