change ``bash headers to ``sh

basics/yes.md

@@ -11,14 +11,14 @@ This is extremely powerful.
 
 If you ever want to automatically install something which persistently nags you with `do you want to do the thing? [y/N]?`, then you can just pipe `yes` into that program, and it will answer 'yes' to all questions.
 
-```bash
+```sh
 yes | $INSTALL_SCRIPT_FILE.sh
 ```
 
 This works best for disposable systems, like VMs or containers.
 Try this on a live system, and you might find out that you should have read that message fully.
 
-```bash
+```sh
 yes | yay
 ```