pkexec: add page (#16347)

Co-authored-by: Fazle Arefin <[email protected]>

Author: Managor

pages/linux/pkexec.md

@@ -0,0 +1,17 @@
+# pkexec
+
+> Execute commands as another user.
+> Asks for password in a GUI if available.
+> More information: <https://polkit.pages.freedesktop.org/polkit/pkexec.1.html>.
+
+- Run command as root:
+
+`pkexec {{command}}`
+
+- Switch user to root:
+
+`pkexec`
+
+- Run command as a specific user:
+
+`pkexec --user {{username}} {{command}}`