Add a primer on rotations

[sfmig]

Is your feature request related to a problem? Please describe.
Understanding rotations can be very tricky, especially if you unfamiliar with coord systems etc. (see e.g. ambiguities). We (with @roaldarbol and @lochhh) thought it would be useful to present and clarify things for animal behaviour scientists.

Describe the solution you'd like
Similar to #25 :

• An appendix document summarising what we have learnt and what we think is useful to know about these topics.
• It would be nice to also add good references of material we found helpful (e.g. quaternions series from 3blue1brown)

It probably needs a bit research and iteration since we need to agree what we want to include and what are our conventions. We think the goal should be more of a primer, with links to good material to dive deeper

Describe alternatives you've considered
Like in #25: Could be added as a chapter if we have more complex analysis in the book. But we think for now making it a deep dive but optional is more friendly.

Additional context

• This tool found by @roaldarbol to explore rotations applied to coord systems seems super useful: https://articulatedrobotics.xyz/tools/rotation-calculator/
• This can be a good inspiration (focuses on the math of quaternions): https://eater.net/quaternions
  • Maybe worth playing with manim?
• For Python, scipy is probably the best way to work with rotations
  • Some examples: seabirds, egocentric coordinate system
• For R, we found these libraries that could be relevant: RSpincalc, onion
• This could also serve as a document for our agreed conventions (for movement and animovement)
  • A related issue from animovement: Rotate coordinates in 3D animovement/anispace#4
  • Some movement related implementations: homography computation - probably we should explain it better as it seems somewhat popular (e.g. this blogpost)