[rocm-libraries] ROCm/rocm-libraries#9634 (commit 636332c)

docs(ck) Updated install steps

## Motivation

The prerequisties for the CK installation were too broad and needed to
be pared down, and two env vars needed to be set after installing from
the nightly artifacts.

Took the opportunity to also delete the docker image section.

JIRA ID : AIROCDOC-3832

This is a retry of https://github.com/ROCm/rocm-libraries/pull/7648 that
had problems.