Merge pull request #25 from VehementHam/patch-1

Add alert for `mkdir -p` in `shell.mdx`.

src/content/docs/en/linux/shell.mdx

@@ -78,6 +78,11 @@ To create a new directory, type `mkdir` followed by the path to the directory.
 mkdir /home/user/Documents/newdir
 ```
 
+<Alert type="info">
+  To create a new directory inside of another new directory (i.e. `.../newdir/newdir2`),  
+  execute `mkdir` with the `-p` flag.
+</Alert>
+
 To move or rename a file or directory, type `mv` followed by the path to the file or directory, and then the new path.
 
 ```zsh