* Added: khmer language to HOWTO page.

Added: khmer language to HOWTO page.

* Changed: khmer iso code from kh to km

* Added Distributed Systems and Bash Shell Scripting in english

* Added Distributed Systems tutorial

* Fixes: #6178

* Upate Julia Quantitative Economics link to be more stable

* Slovenian language introduced

* Additional changes on Slovenian language

* add devMode podcast

* change devMode.fm podcast link

* add jadi apple podcast

* change radio geek url into anchor.fm

* new persian python free course added

* new farsi python course added

* Update courses/free-courses-fa_IR.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* added new farsi course(.idea removed)

* added new farsi python course with access note

* added new farsi python course with access note
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Added book: Foundations of Computational Books

* Update free-programming-books-subjects.md

* Create free-courses-gr.md and added JavaScript course

check_urls=free-programming-books.md free-programming-books-gr.md

* Update free-courses-gr.md

* Bumps review EbookFoundation#5693

Recover deleted PR head:
git fetch upstream pull/5693/head:pr/anneiric/5693

anneiric <69729163+anneiric@users.noreply.github.com>

* fix(listings): greek language code `gr` > `el`

language code for greek is `el` not `gr`. See: EbookFoundation/free-programming-books#6070

Applies https://github.com/EbookFoundation/free-programming-books/pull/5693#issuecomment-938647297

* feat(courses): Add greek entry

Link recent created greek courses listing `books/free-courses-el.md` into `README.md`

Resolves EbookFoundation/free-programming-books#5693

* feat(courses): Add greek entry

Link `courses/free-courses-el.md` into `README.md`

Resolves EbookFoundation/free-programming-books#5693
Co-authored-by: Nanneiric <69729163+anneiric@users.noreply.github.com>

* Include Textbook for System Programming in C at the University of Illinois

* Correct book title and add authors

* kentc podcast

* change with kent's site

* Add RxJS course "Asynchronous Programming: The End of The Loop"

* remove link to author's social

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

* Update free-courses-en.md

* remove subcategory for cycle js

* Removing 404 link Errors from ES

404 Errors 
http://lya.fciencias.unam.mx/jloa/publicaciones/introduccionJava.pdf
http://lya.fciencias.unam.mx/jloa/publicaciones/teoria.pdf
http://lya.fciencias.unam.mx/jloa/publicaciones/automatasyLenguajes.pdf

* Updating https:// links for fciencias.unam.mx 

Removing one link

* add missing blank line

* add missing blank line

* adding POO y MVC en PHP - Eugenia Bahit (PDF)

* Update books/free-programming-books-es.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Added CMake courses

* fixed alphabetical order build error

* fixed build error (I hope)

* removed riptutorials

* Fix links for english casts

* Removing trailing slash

* add book Mastering Node

* update entry for Mastering Node

Moved 
[Solidity Tutorial - A Full Course on Ethereum, Blockchain Development, Smart Contracts, and the EVM](https://www.youtube.com/watch?v=ipwxYa-F1uY) - Gregory McCubbin @ freeCodeCamp.org & Dapp University (YouTube)
to courses from tutorials,
Thanks :)

* Update free-programming-books-subjects.md

* Update free-programming-books-langs.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update books/free-programming-books-langs.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Update books/free-programming-books-subjects.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Update books/free-programming-books-subjects.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Update books/free-programming-books-subjects.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* added python course

* Update courses/free-courses-tr.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

Moving course to javascript section

* Hindi topicwise playlists of algorithms added, Hindi topicwise playlists of data-structures added

* Update free-courses-hi.md

* changed title of C++

* Update free-courses-hi.md

* space removed, original titles added

* Update free-courses-hi.md
Co-authored-by: NEric Hellman <eric@hellman.net>

I added "Search Engines: Information Retrieval in Practice" by W. Bruce Croft, Donald Metzler, Trevor Strohman to the subject list.

* Add Python 3 Book

Python 3 book from DigitalOcean.

* Update list to add learning Processing resource

Reattempted.

* Update podcasts-screencasts-en.md

Changed playlist and added the contributor name.

* Alphabetize Processing playlists

Alphabetize the processing playlists added.

* Removed Processing Resource

Removed Processing YouTube links from screencasts.

* Updated free-courses with Processing Resource

Added processing resource in free courses list.

* Update free-courses-en.md Readme

Added Deno course from freeCodeCamp.

* Update free-courses-en.md

Removed Deno resource from master branch.

* Update free-courses-en.md

Add Deno course from FreeCodeCamp.

* Added Node.js eBook

* Update ebook listing with file formats
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Corrected Alphabetisation
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Add nim playground to playground list

* Add correct spacing between headers

* Add organisation to link
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Add Android App Development by ProgramMe Programming

* Update Instructor's Name: Android App Course
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Add the first julia cource

* Update courses/free-courses-ru.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* added Communicating using Markdown Course

* Update free-courses-en.md

* Update courses/free-courses-en.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Add Kotlin Quick Reference online book.

https://kotlin-quick-reference.com/

* Update free-programming-books-langs.md

* Update books/free-programming-books-langs.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* Update free-programming-books-langs.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>