The textbook written for the course on python is freely licensed ([CC-BY-NC-ND](https://creativecommons.org/licenses/by-nc-nd/4.0/)), so it seems worth being added.

* Misc category cleanup

* Fix

* Removed the CS For All book

It's just a set of problems and the textbook is no longer available for free online.

This course now has restricted access. HTTP Response: Request failed with status code 403.

Page not found for link http://tableless.com.br/o-que-nodejs-primeiros-passos-com-node-js

* New books from the Syncfusion's Succinctly series

* Fix

* More books

* Cleanup

* Fixes

* One more fix

* O'Reilly cleanup

* Added the missing PDF annotation

* New MIT Open Access books

* Alphabetic fix

* Danish programming books added

* Danish link to README

* Update a Java book URL - #2990

Changes:
- The book 'Object-Oriented vs. Functional Programming' has a .csp link
- Also a sign-up is required to read the book since it's hosted at oreilly.com
- The contributing guide is against a hosting service and required sign-up.
- That is why this PR is created.

* remove ? link
Co-authored-by: NEric Hellman <eric@hellman.net>

* added spring data reference

* satisfy linter
Co-authored-by: NEric Hellman <eric@hellman.net>

- Fixed a couple of links to topics in the page
- Removed a course that is accessible only to students of the university which made the course
- Added three courses

Some of our Udacity listings added '(Udacity)' as and access note. This PR makes the practice uniform. We can consider other platforms case by case. In general, I feel that when the platform offers additional services that make it matter what platform a course is on, the addition of an access note is useful.

Comments welcome on appropriateness of  the access notes.

* Fixed non-working links

* Newline fix

* Fixed a link missing https://

* New AI course

* New Finnish AI course

* Elements of AI course in German

* Trailing slash fix

* Trailing slash fix

* Update free-programming-books-fi.md

* Fixed a link to author's own page

Found the original link from author's own page so there's no need to link to ResearchGate.

* Newline fix