Update 2022-09-06-nushell-0_68.md

Author: sophiajt

blog/2022-09-06-nushell-0_68.md

@@ -150,7 +150,7 @@ Here is a table that summarizes the changes:
 
 To bring more familiarity with other languages, we added the option to define command signatures with parentheses `()` instad of only braces `[]`:
 ```
-def foo (x: int) { x + 100 }
+def foo (x: int) { $x + 100 }
 ```
 
 The square braces `[]` continue to work as well.