remove trailing whitespace

Author: coke

doc/Type/Proc.pod6

@@ -74,7 +74,7 @@ sub shell(
         Hash() :$env = %*ENV
     --> Proc:D)
 =end code
-    
+
 C<new> creates a new C<Proc> object, whereas C<run> or C<shell> create one and spawn it
 with the command and arguments provided in C<@args> or C<$cmd>, respectively.