current ng-newsletter link results in a 500 page. found an alternate link, but I suspect it is temporary until the newsletter fixes their 500, so we may not want to update the link. either way, this PR addresses #3400

* Remove dead link from free-programming-books-tr.md

* Change Django heading to same size as other headings

* Update link for Learning Deep Architectures

* revert django heading

* undo space add

* Adding OpenMP 5.0

* Adding PDF indicator

✔ Updated link of A Scala tutorial for Java programmers

✔ Updated link of Scala by Example

* Changed to new I Love Ruby website

* satisfy linter

* Added the React.js Succinctly.

* Update free-programming-books.md

* Included the Flutter, Azure Functions and Elixir Succinctly.

* Added two more books under flutter.

* Add Book Professional Development GitLab Handbook

* moved to Open Source Ecosystem and fixed warning

* Update free-programming-books.md

Add gidti eBook

* Add author name

* Add Mathematics Seven Sketches in Compositionalit

* Update free-programming-books.md

* Add Cloud Design Patterns

* fixed blanks

* Making games with TypeScript

* Remove trailing slash

link to more up to date version with better font

old: http://www.ethoberon.ethz.ch/WirthPubl/AD.pdf
new: https://inf.ethz.ch/personal/wirth/AD.pdf

previous docs were from 2005, found more recent docs from 2018

* Add a free JS resource on the list of free JS books.

* Alphabetical orderFix

"let's" > "leaflet"

* orderFix with eyes wide open.

T > A.

there were only links to v1.x django docs, so I added a link to the django 2.2 pdf docs

url = https://buildmedia.readthedocs.org/media/pdf/django/2.2.x/django.pdf

* added C Programming Language book PDF source

with reference to issues [3189](https://github.com/EbookFoundation/free-programming-books/issues/3189)
Added C Programming current standard PDF source.

* Add PDF indication

* Update deprecated links to Google's Android courses

* Renaming link to codelab in alphabetical order

* Rearrange in alphabetical order

* Remove Android Developer Fundamentals from books

* Add Android Developer Fundamentals to courses list

* Adding Harvard GSE Scratch Book

* adding raspberry pi press book

* spelling sorting doesn't ignore "an" as first word of title

* add introduction to Ada course book

* Change book to add

Add Ada for the C++ or Java Developer book instead.

* add author name to an ada book

* Update free-programming-books.md

* Update free-programming-books.md

* Update free-programming-books.md

Sorry for the error, fixed the spaces so that the linting will now work.

* Learn Azure in a Month of Lunches Book Added

* Learn Azure in a Month of Lunches Book Added

* Author Added

* IPv6 for IPv4 Experts english has been added

* IPv6 for IPv4 Experts russian has been added

* IPv6 for IPv4 Experts russian URL change

* IPv6 for IPv4 Experts english URL change

* Removed non-working book link

The link gets redirected to www.oreilly.com. The 1st chapter is still available to read online at https://www.oreilly.com/library/view/python-cookbook-3rd/9781449357337/ch01.html

* Removed another redirected book

The URL is redirected to http://jasonrbriggs.com/python-for-kids/ which is not available for free.