Please include new level 1 header in error message when a new level 1 header is added to a markdown document

[jayhawk87]

Describe the bug

When validating a markdown document against a markdown template, if the document has additional level 1 headings, the error
output only states that new headers have been added. It is left to the reader to figure out which one has been added.

To Reproduce

Steps to reproduce the behavior:

1. Establish a markdown template
2. Create a document from that template
3. Add a new level one header to the end of the document
4. Validate the document against the template and see something like the following result:

New headers of level 1 were added to the markdown instance: /mnt/arch-design/ssad/privileged-access-gateway/privileged-access-gateway-ssad.md.
INVALID: arch-design/ssad/privileged-access-gateway/privileged-access-gateway-ssad.md

Expected behavior

Expect to see additional line(s) showing the added headers to make it easy to find in the document.

Screenshots / Logs.

None needed

Environment

• OS: [e.g. iOS] MacOS
• Python version: 3.11.11
• Installed packages: standard trestle install

[jpower432]

Thanks for the issue @jayhawk87. I was able to reproduce with our community repo templates using the steps you provided.