Adding fretboard features

Hi community,
First of all, my version of HedgeDoc is: 1.8.2 2021-05-11

I was using CodiMD and I was interested in a feature called “fretboard” (for guitar training). So I installed HedgeDoc on a VPS which is to become the reference for the HackMD/CodiMD project (Am I right ?).

I saw that there was differences and features unavailable / disabled.

I tried to look on the forum or the documentation but I found nothing about it.

So I have a question: Is there a way to enable this feature or should I work on it to implement it based on CodiMD version ?

( Is there any reason having removed this feature in HedgeDoc or is it just not implemented yet ? )

Thank you, Greetings from France :blush: :baguette_bread: