Rename the baseline markdown files

[adhilto]

🗣 Description

Shorten the file names of the baseline markdown files (e.g., change "Common Controls Minimum Viable Secure Configuration Baseline v0.2.md" to "commoncontrols.md")

💭 Motivation and context

Closes #314.

🧪 Testing

Ran ScubaGoggles, verified that:

• It successfully runs to completion
• The links to the group names included in the are correct (they won't work as is because they're pinned to the v0.2.0 release, but if you edit the url and replace that with "314-rename-the-baseline-markdown-files" they work)
• The links in the Readme files still work

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• If applicable, All future TODOs are captured in issues, which are referenced in the PR description.
• The relevant issues PR resolves are linked preferably via closing keywords.
• All relevant type-of-change labels have been added.
• I have read and agree to the CONTRIBUTING.md document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• Tests have been added and/or modified to cover the changes in this PR.
• All new and existing tests pass.

✅ Pre-merge Checklist

• This PR has been smoke tested to ensure main is in a functional state when this PR is merged.
• Squash all commits into one PR level commit using the Squash and merge button.

✅ Post-merge Checklist

• Delete the branch to clean up.
• Close issues resolved by this PR if the closing keywords did not activate.

[buidav]

Hopefully we didn't hard write the absolute URL anywhere else.

[snarve]

Looks good, reports are working as expected.