Add NumberOfPoints

[gtauzin]

Reference issues/PRs

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Description Add NumberOfPoints.

Screenshots (if appropriate)

Any other comments?

Checklist

• [x] I have read the guidelines for contributing.
• [x] My code follows the code style of this project. I used flake8 to check my Python changes.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed. I used pytest to check this on Python tests.

[ulupo]

Attempting to smuggle MNIST into this? Thought I wouldn't see it? XD

[gtauzin]

Attempting to smuggle MNIST into this? Thought I wouldn't see it? XD

Whaaaaaat? I would never do that. Where do you see this? xD

[wreise]

@ulupo would you mind having a look?