examples: Call Terminal::reset_mode instead of relying on Drop

At some point recently I got rid of the Drop stuff. We need to reset the
mode or else Windows powershell crashes for me when trying to claim
CONIN$ twice. (Run an example before this commit and then run regular
`hx`).

examples/detect-features.rs

@@ -70,8 +70,7 @@ fn main() -> io::Result<()> {
             other => eprintln!("unexpected event: {other:?}\r"),
         }
     }
-    terminal.enter_cooked_mode()?;
-    drop(terminal);
+    terminal.reset_mode()?;
     println!("Detected features: {features:?}");
 
     Ok(())

examples/event-read.rs

@@ -131,6 +131,8 @@ fn main() -> io::Result<()> {
         ))),
     )?;
 
+    terminal.reset_mode()?;
+
     Ok(())
 }