Midline offsetfor arrowhead

[BethencourtFlorian]

For now, the offset option can only take a given offset from the start or the end of the line in either meters or pixels.
But is it possible to write something like
var polyline = L.polyline(latlngs).arrowheads({offsets: {end: '50%'}})
?
Or maybe a way to get the polyline length and calculate an offset from there ?
Thanks in advance

[slutske22]

Currently a % offset is not available. I'm out of bandwidth, but if you want to take a crack at it and open a PR, go for it