Add highlighting to last code-block

SC1064.md

@@ -32,8 +32,10 @@ If you are trying to do something else, look up the syntax for what you are tryi
 
 POSIX allows the body of a function to be any compound command, e.g. `foo() for i; do :; done`. Since this usage is rare, ShellCheck intentionally requires the body to be `{ ..; }` (or `( ..; )`):
 
-    foo() {
-      for i; do :; done
-    }
+```sh
+foo() {
+  for i; do :; done
+}
+```
 
 This additional structure requirement helps improve error messages and suggestions by not parsing down a path that less advanced users wouldn't expect.