Construct rotation that aligns two vectors

[Kolaru]

Sometimes it is nice to have the rotation that aligns two vectors (e.g. when aligning randomly oriented data according to a chosen frame).

If it is a good fit for the package, I can try to make a PR. I already have some code doing it laying somewhere.

[hyrodium]

This function seems already implemented as Rotations.rotation_between.

julia> using Rotations, LinearAlgebra

julia> r = Rotations.rotation_between([1,0,0],[0,1/√2,1/√2])
3×3 QuatRotation{Float64} with indices SOneTo(3)×SOneTo(3)(QuaternionF64(0.707107, 0.0, -0.5, 0.5, false)):
 -1.11022e-16  -0.707107  -0.707107
  0.707107      0.5       -0.5
  0.707107     -0.5        0.5

julia> r * [1,0,0]
3-element StaticArraysCore.SVector{3, Float64} with indices SOneTo(3):
 -1.1102230246251565e-16
  0.7071067811865475
  0.7071067811865475

julia> dot(rotation_axis(r), [1,0,0])
3.437762736252422e-63

julia> dot(rotation_axis(r), [0,1/√2,1/√2])
0.0

[hyrodium]

Please comment here if Rotations.rotation_between is not sufficient.