fix(handlers/main)!: Change exit key to `q`

`Esc` is bound to exit a deeper mode (like `insert` or `command`) and
return to `normal` mode. This however is rather inconvenient,
when `Esc` also exits Trinitrix in general, as spamming `Esc` then
becomes impossible.
This changes also puts Trinitrix more in line with vim (although vim
does not allow exiting with `q`).

BREAKING CHANGE: To exit press `q` instead of `Esc`.

src/app/events/event_types/event/handlers/main.rs

@@ -58,7 +58,8 @@ pub async fn handle_command(
 pub async fn handle_normal(app: &mut App<'_>, input_event: &CrosstermEvent) -> Result<EventStatus> {
     match input_event {
         CrosstermEvent::Key(KeyEvent {
-            code: KeyCode::Esc, ..
+            code: KeyCode::Char('q'),
+            ..
         }) => {
             app.tx
                 .send(Event::CommandEvent(Command::Exit, None))