fix ansible-vault diff

@natefoo this is why it didnt work during gat

topics/admin/tutorials/ansible-galaxy/tutorial.md

@@ -1143,6 +1143,12 @@ The configuration is quite simple thanks to the many sensible defaults that are
 >    > to ensure colleagues get a copy of the file too. Just **be sure**
 >    > `.vault-password.txt` is listed in your `.gitignore` file!
 >    >
+>    > You will also need to run this command to define how the `ansible-vault` differ should work:
+>    >
+>    > ```
+>    > git config --global diff.ansible-vault.textconv "ansible-vault view"
+>    > ```
+>    >
 >    > If you have more vault secrets, you can adjust this line (or add more,
 >    > wildcards are supported) to list all of your secret files. This tells
 >    > `git` to use `ansible-vault` to diff the two files, as you can see in