Fix flag in README.md

README.md

@@ -7,9 +7,9 @@ Run the command with `{}` where you want your arguments to be. Currently, only o
 
 Example (Ion syntax):
 ```ion
-parallel -progress 'echo {}' {1..1000}
+parallel --progress 'echo {}' {1..1000}
 ```
 or in POSIX shells (with the seq command):
 ```bash
-parallel -progress 'echo {}' $(seq 1 999)
+parallel --progress 'echo {}' $(seq 1 999)
 ```