docs: fixing a typo
@@ -220,7 +220,7 @@ impl<'help, 'app> Parser<'help, 'app> {
if foundx2 && !p.is_set(ArgSettings::Required) {
assert!(
p.is_set(ArgSettings::Required),
- "Found unrequred positional argument with a lower \
+ "Found unrequired positional argument with a lower \
index than a required positional argument by two or more: {:?} \
index {:?}",
p.name,
