[Feature request] Automatically exclude folders that do not contain markdown files

[cathywu]

My vault contains many subfolders for auxiliary files (images, PDFs, code, etc.), and they currently clutter up the generated Waypoint. It would be great if these subfolders are excluded from the generated Waypoint. One way I can imagine implementing this is to exclude Waypoint headings for folders that do not contain any markdown files. This could be exposed as an optional setting.

Here is a small snippet example of subfolders listed via Waypoint that do not contain any markdown files, cluttering up the Waypoint:

Finally, thank you for the great project! It's a huge help for taming a growing vault.