Reformat all code to use shell instead of sh

snippets/view-merged-branches.md

@@ -8,11 +8,11 @@ Prints a list of all merged local branches.
 - Use `git branch -a --merged` to display a list of all merged local branches.
 - Use arrow keys to navigate, press <kbd>Q</kbd> to exit.
 
-```sh
+```shell
 git branch -a --merged
 ```
 
-```sh
+```shell
 git checkout master
 git branch -a --merged
 # patch-1