Updated free-courses-en.md (#9019)

* Updated free-courses-en.md

* made the required changes

* Update courses/free-courses-en.md

Co-authored-by: Eric Hellman <eric@hellman.net>

courses/free-courses-en.md

@@ -998,6 +998,7 @@
 * [Introduction To Linux](https://www.edx.org/course/introduction-to-linux/) - The Linux Foundation (edx)
 * [Linux Administration Tutorial Videos](https://www.youtube.com/playlist?list=PL9ooVrP1hQOH3SvcgkC4Qv2cyCebvs0Ik) - edureka!
 * [Linux Command Line](https://www.udemy.com/course/command-line/) - Adam Eubankas (Udemy)
+* [Linux Command Line Tutorial For Beginners](https://www.youtube.com/playlist?list=PLS1QulWo1RIb9WVQGJ_vh-RQusbZgO_As) - Programming Knowledge
 * [Linux Tutorial for Beginners - Learn Linux and the Bash Command Line](https://ryanstutorials.net/linuxtutorial) - Ryan Chadwick
 * [Linux Tutorials and Projects](https://www.udemy.com/course/linux-tutorials/) - Jason Cannon (Udemy)
 * [Red Hat Enterprise Linux Technical Overview](https://www.udemy.com/course/red-hat-enterprise-linux-technical-overview/) - Red Hat Inc. (Udemy)