[Feature request]: Implement OneNote to Butterfly migration

[claws99]

Is your feature request related to a problem? Please describe

Until recently, OneNote is the only pen-based notetaking free app which is available on all platforms (except linux). Hence lot of old notes for lot of users is stuck in OneNote. And lot of users are still hoping to better features from Microsoft.

I myself strugged a lot porting that notes.

There are few migrators online but they don't do the job properly.

Describe your feature request!

Since Butterfly is truly a classplatform app, it provides a good substitute to OneNote.

If we could provide an import mechanism to OneNote users. We'll win a lot of users.

Penstrokes in OneNote are stored in some ink format. Need to explore more. But its definitely possible.

Additional context

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[CodeDoctorDE]

I found a specification on the microsoft website: https://interoperability.blob.core.windows.net/files/MS-ONE/%5bMS-ONE%5d.pdf
If we implement this we need to show a guide how to download this file (because microsoft makes it really hard):

• If you use windows, install the Onenote app (not the onenote for windows 10 app) and click on export and then on onenote file
• If you are not on windows, download the documents folder (you can't download the real onenote file for some reason) and extract it.

I added the good first issue Good for newcomers label here too. It's the same steps as in #314 (comment)

[CodeDoctorDE]

I need to say: The importer will be very difficult.
The .one file is not very good readable, it's binary data with a structure that only onenote understands.
The .mht file format is parsable but I don't see how to extract the strokes out of it.

If anyone has time looking at it, feel free to answer here what you found out