## What does this PR do?
Add resource(s) | Remove resource(s) | Add info | Improve repo

## For resources
### Description

### Why is this valuable (or not)?

### How do we know it's really free?

### For book lists, is it a book? For course lists, is it a course? etc.

## Checklist:
- [ ] Read our [contributing guidelines](https://github.com/EbookFoundation/free-programming-books/blob/master/CONTRIBUTING.md)
- [ ] Search for duplicates.
- [ ] Include author(s) and platform where appropriate.
- [ ] Put lists in alphabetical order, correct spacing.
- [ ] Add needed indications (PDF, access notes, under construction)

## Follow-up

- Check the status of GitHub Actions and resolve any reported warnings!