prevent users from running as debug

We give a friendly message now. If you need to run as debug,
use `cargo run -- --debug` or `./target/debug/notedeck --debug`

We also remove the callstack feature because it doesn't seem
like you need it for widget callstacks.

Fixes: aafddf5acb ("debug: add crate features which enable egui DebugOptions")
Signed-off-by: William Casarin <jb55@jb55.com>

src/app_style.rs

@@ -70,17 +70,10 @@ pub fn create_custom_style(ctx: &Context, font_size: fn(&NotedeckTextStyle) -> f
         ..Interaction::default()
     };
 
-    // debug: show callstack for the current widget on hover if all
-    // modifier keys are pressed down.
-    #[cfg(feature = "debug-widget-callstack")]
-    {
-        style.debug.debug_on_hover_with_all_modifiers = true;
-    }
-
-    // debug: show an overlay on all interactive widgets
-    #[cfg(feature = "debug-interactive-widgets")]
+    #[cfg(debug_assertions)]
     {
         style.debug.show_interactive_widgets = true;
+        style.debug.debug_on_hover_with_all_modifiers = true;
     }
 
     style