[Feature request] Add an option to ignore empty folders

[AdamCodd]

Hello,

I looked around but I didn't find this option. Sometimes I get a tree like this:
Generator-music/
├─ old/
├─ Templates/
├─ Videos/
├─ add-overlay.py
├─ cover_extract.py
├─ description-generator.py
├─ DL-comments.py
├─ lyrics-to-xml.py
├─ pipeline-gui.py
├─ process.py
├─ STT_interface.py
├─ thumbnail-generator.py
├─ trim-gui.py
└─ video_downloader.py

Since I added the files from old and templates to .gitignore and I set "fileTreeExtractor.ignoredBy": "both" I end up with empty folders like this in the tree. Sure I could add the folders manually in fileTreeExtractor.ignoredItems, but I thought it'd be easier to simply be able to ignore empty folders when generating the tree.

This is a really good extension btw. Thanks.