Examples demonstrating (Mis)Orientation.from_align_vectors()

[hakonanes]

Description of the change

Added two examples to the examples gallery (from PR comments https://github.com/pyxem/orix/pull/401#pullrequestreview-1138061052 and https://github.com/pyxem/orix/pull/401#pullrequestreview-1139428658):

• Get an orientation from two sets of vectors, one in the sample reference frame and the other in the crystal reference frame. Uses Orientation.from_align_vectors().
• Get a misorientation from two sets of vectors, one in each of the two crystal reference frames. Uses Misorientation.from_align_vectors().

I've also added the possibility to pass symmetry to Orientation.from_scipy_rotation() and Misorientation.from_scipy_rotation(). Rotation.from_scipy_rotation() is also updated, so that all these three methods have custom docstrings. I've also made sure these methods return a tuple instead of a list if either of return_rmsd or return_sensitivity are True.

Progress of the PR

• [x] Docstrings for all functions
• [x] Unit tests with pytest for all lines
• [x] Clean code style by running black via pre-commit

For reviewers

• [ ] The PR title is short, concise, and will make sense 1 year later.
• [ ] New functions are imported in corresponding __init__.py.
• [ ] New features, API changes, and deprecations are mentioned in the unreleased section in CHANGELOG.rst.
• [ ] Contributor(s) are listed correctly in __credits__ in orix/__init__.py and in .zenodo.json.