Bug: v4 Folder note breaking for non-MD files in directories

[maggiedelano]

Describe the bug
When using BC folder notes, breadcrumb graph generation sometimes stalls out, likely due to processing files that either don't exist or aren't md files.

To Reproduce
Steps to reproduce the behavior:

1. Add a non md file to a folder.
2. Include BC-folder-note-field: down for a note in that folder.
3. Rebuild graph.
4. See error in console.

Expected behavior
Folder notes should work on all the markdown files in the folder, regardless of other folders or files present.

Screenshots

Desktop (please complete the following information):

• OS: Mac 13.4.1
• Version: Breadcrumbs 4.0.68-beta

[SkepticMystic]

Thanks for the detailed issue! Makes sense, should be simple to fix