Update cheatsheets

tldr/linux/su

@@ -23,3 +23,15 @@ source: https://github.com/tldr-pages/tldr.git
 - Execute a command as another user:
 
 `su - {{username}} {{[-c|--command]}} "{{command}}"`
+
+- Switch to a given user and use a specific shell (e.g., zsh, fish, bash):
+
+`su {{[-s|--shell]}} /{{path/to/shell}} {{username}}`
+
+- Display help:
+
+`su {{[-h|--help]}}`
+
+- Display version:
+
+`su {{[-V|--version]}}`