[chapters.lua] Ability to generate XML chapters and embed them in a MKV file with mkvpropedit

[KonoVitoDa]

And I'll also use the opportunity to report a problem I found: the bake-chapters function was intended to embed the chapters file into the video file? Because I used it to embed the chapters into a MKV file and while it worked to generate the new file, no chapters were shown on the new file (at least no the new chapters I made, but the old ones that were already present). I checked the MKV on MKVToolNix and it had the metadata file embedded on it, but seems like MKV needs the XML chapters instead, so it would be much appreciated if you could add support for XML chapter files as well! And what would make the script even better would be if you also added the ability to use mkvpropedit to directly write the chapters into the MKV, and it can make it in just a second! The CLI commands it uses to remove the old and embed the new chapters are respectively: mkvpropedit.exe input.mkv --chapters "" mkvpropedit.exe input.mkv --chapters chapters.xml