Merge pull request #950 from p1utoze/linux

Added new resource in Unix.md

Unix.md

@@ -5,6 +5,8 @@
 The Unix family includes several incredibly popular, open-source operating systems (including Ubuntu, Debian, and Redhat).
 Here are #a few resources on how to use Unix systems and operate the command line.
 
+- [Linux Journey](https://linuxjourney.com/): A comprehensive Linux shell concepts tutorial with interactive command line lessons creating fun and free learning for beginners to advanced users.
+
 - [EDX: Introduction to Linux](https://www.edx.org/course/introduction-to-linux): great intro to upper-intermediate course on what the hell is Linux
 
 - [Basic Unix Commands](https://www.maths.ox.ac.uk/system/files/legacy/2356/basic-unix.pdf): a guide from Oxford University on Unix commands