Move pages under tldr, lint run.sh, update docs

tldr/linux/unshadow

@@ -0,0 +1,17 @@
+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# unshadow
+
+> Utility provided by the John the Ripper project to obtain the traditional Unix password file if the system uses shadow passwords.
+> More information: <https://www.openwall.com/john/>.
+
+- Combine the `/etc/shadow` and `/etc/passwd` of the current system:
+
+`sudo unshadow /etc/passwd /etc/shadow`
+
+- Combine two arbitrary shadow and password files:
+
+`sudo unshadow {{path/to/passwd}} {{path/to/shadow}}`