[DOC] Add NGC references back to README

[BartleyR]

Report needed documentation
We removed the NGC references from the getting started section temporarily as to avoid confusion on the multiple paths to get started. The removed link directed users here: https://catalog.ngc.nvidia.com/orgs/nvidia/teams/morpheus/collections/morpheus_. This is where a user would go if they want to use Helm charts to run Morpheus in a K8s environment.

Describe the documentation you'd like
This link and wording around it should be added back into the README.md file once we can decide on the wording to avoid potential confusion with users mixing and matching paths to get started.

[mdemoret-nv]

To be clear, this issue should separate the documentation pieces that should be seen only after release from the pieces that are seen during development. This means:

1. Remove all references of NGC and pre-built containers from the root README
2. Add the NGC references to the root of the docs/index.rst
3. Add a link to NGC in each of the releases pages
4. Ensure all version numbers match in the repo