docs(devops): add videos to scripting pisince

subjects/devops/count-files/README.md

@@ -45,5 +45,6 @@ $ wc -lwc example.md
 
 ### References
 
+- [Wildcards](https://www.youtube.com/watch?v=DjBg8_ZtSDE)
 - [Find](https://manned.org/find).
 - [wc](https://www.gnu.org/software/coreutils/wc).

subjects/devops/json-researcher/README.md

@@ -59,3 +59,7 @@ You may need to use pipes `(|)` and the logical operator `&&`.
 
 > You have to use Man or Google to know more about commands flags, in order to solve this exercise!
 > Google and Man will be your friends!
+
+### References
+
+- [Pipes](https://www.youtube.com/watch?v=ou9o20pzxeg)

subjects/devops/strange-files/README.md

@@ -58,5 +58,6 @@ $ touch foo\!\\.txt
 
 ### References
 
+- [Escape Characters](https://www.youtube.com/watch?v=ZenUrQeHl7c)
 - [ls](https://www.gnu.org/software/coreutils/ls).
 - [touch](https://www.gnu.org/software/coreutils/touch).