Remove documentation for yaml config files in `vdb_upload` pipeline until #1752 is resolved

Description

Morpheus issue #1752 renders the --vdb_config_path flag broken, remove it from documentation until the bug is resolved.
Replace stubbed markdown README.md files for rag and vdb_upload pipelines with symlinks to the readme's in the examples dir.
Replace broken link for generating NGC keys with https://docs.nvidia.com/ngc/gpu-cloud/ngc-user-guide/index.html#generating-personal-api-key which I believe is the correct url.
Fix anchor urls in the vdb_upload readme

I am familiar with the Contributing Guidelines.
When the PR is ready for review, new or existing tests cover these changes.
When the PR is ready for review, the documentation is up to date with these changes.