Added Hash derive to Key (#156)

Author: Kyllingene

src/kb.rs

@@ -3,7 +3,7 @@
 /// This is an incomplete mapping of keys that are supported for reading
 /// from the keyboard.
 #[non_exhaustive]
-#[derive(Clone, PartialEq, Eq, Debug)]
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
 pub enum Key {
     Unknown,
     /// Unrecognized sequence containing Esc and a list of chars