fix(primitive_types): clean up

exercises/primitive_types/primitive_types1.rs

@@ -4,7 +4,6 @@
 
 // I AM NOT DONE
 
-#[test]
 fn main() {
     // Booleans (`bool`)
 

exercises/primitive_types/primitive_types6.rs

@@ -1,7 +1,7 @@
 // primitive_types6.rs
 // Use a tuple index to access the second element of `numbers`.
 // You can put the expression for the second element where ??? is so that the test passes.
-// Execute `rustlings hint primitive_types6` for hints!
+// Execute `rustlings hint primitive_types6` or use the `hint` watch subcommand for a hint.
 
 // I AM NOT DONE