Headings levels validation is not working properly

[AleJo2995]

Describe the bug

When trying to use trestle author folders validate command, there´s a bug happening while performing validation. Heading levels are being respected properly in the documentation, but actual validation is failing.

To Reproduce

Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior

Validation should consistently pass without giving errors

Screenshots / Logs.

Current logs:

trestle.core.markdown.markdown_validator:209 WARNING: Headings in the instance: **_path-location_** were shuffled or modified.
Instance does not have required template heading "###### Additional Outputs". Check if this heading was modified/present in the instance.
Please note that no changes to template headings are allowed, including extra spaces.
INVALID: defect_checks/vuln/vuln.md

Environment

• OS: [e.g. iOS]
• Python version:
• Installed packages: