Added Option to specify custom FolderNote Filename

[jyyyeung]

Added new Folder Note Style option: "Custom Filename" which allows user to specify the filename of their folder note.

[dhmmasson]

I would be very interested in that feature. My use case is that gitbook use README as folder note.

[YIRU69]

Same.

[leolaurindo]

Very nice feature. Eager to seeing this live

[abbeyroad7]

This would be huge for me. +1

I'm using Quartz to publish my notes and it uses Index as the filename for folder notes. I've had to disable navigation in Quartz because it breaks when I use this plugin.