Remove "I AM NOT DONE" and the verify mode and add AppState

exercises/08_enums/enums1.rs

@@ -2,8 +2,6 @@
 //
 // No hints this time! ;)
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 enum Message {
     // TODO: define a few types of messages as used below

exercises/08_enums/enums2.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint enums2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 enum Message {
     // TODO: define the different variants used below

exercises/08_enums/enums3.rs

@@ -5,8 +5,6 @@
 // Execute `rustlings hint enums3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 enum Message {
     // TODO: implement the message variant types based on their usage below
 }