* 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

* Update free-podcasts-screencasts-pt_BR.md

* Update free-podcasts-screencasts-pt_BR.md

* Free Finnish ebooks

* A few more Finnish books

* New Packt books

* Alphabetic order fix

* Added the rest of the free Packt ebooks

Microsoft Dynamics 365 Enterprise Edition Financial Management - Third Edition was left out because it's not really relevant.

* New section fix

* Updated the missing APL books

* Removed the trailing slash

* New Packt books

* Packtpub account mentions added

* New Python books from Packt

* Fixed alphabetical order