Updated header level to fit rest of the page

[392781]

Describe your changes

This is a minor change regarding the header levels. I believe the intent was to have levels:

Selecting an Image

• Core Stacks
  • CUDA Enabled Variant
  • jupyter/docker-stacks-foundation
  • jupyter/base-notebook
  • jupyter/minimal-notebook
  • ...
• ...

The current iteration seems to indicate that jupyter/... derives from the "CUDA Enabled Variant" header when really it is part of the core stack.

In general, I would propose a reorganization of this particular page for additional clarity (perhaps in a future pull request). Mainly I would suggest just moving certain things around and changing some of the header levels.

Issue ticket if applicable

N/A

Checklist (especially for first-time contributors)

• I have performed a self-review of my code
• If it is a core feature, I have added thorough tests
• I will try not to use force-push to make the review process easier for reviewers
• I have updated the documentation for significant changes

[mathbunnyru]

Thanks, merged.