generics1 rewrite and solution

rustlings-macros/info.toml

@@ -734,8 +734,13 @@ test = false
 hint = """
 Vectors in Rust make use of generics to create dynamically sized arrays of any
 type.
+If the vector `numbers` has the type `Vec<T>`, then we can only push values of
+type `T` to it. By using `into()` before pushing, we ask the compiler to convert
+`n1` and `n2` to `T`. But the compiler doesn't know what `T` is yet and needs a
+type annotation.
 
-You need to tell the compiler what type we are pushing onto this vector."""
+`u8` and `i8` can both be converted to `i16`, `i32` and `i64`. Choose one for
+the generic of the vector."""
 
 [[exercises]]
 name = "generics2"