Create a placeholder "baselines" folder at the top-level of the repo, with a README linking to the nested baseline document location

[buidav]

Originally posted by @adhilto in #499 (comment)

💡 Summary

Create a placeholder "baselines" folder at the top-level of the repo, with a README linking to the actual baselines folder.

• See https://github.com/cisagov/ScubaGear/tree/main/baselines for reference.
• CISA's website refers users to GitHub to view the baslines, we want it to be easy for users to find the baselines
• Some third-party websites already link to that folder. If we put a README there those links won't break. For example: https://www.googblogs.com/page/12/

Motivation and context

To make the SCuBA GWS baselines easily discoverable from main.

Implementation notes

Create a baselines folder in the root directory and link to the nested markdowns in the scubgoggles directory.

Acceptance criteria

When the folder and README noted in Implementation Notes is created.