conforms file names to consistant standard

ui/menus/OptionsMenu/keybind_popup.gd

@@ -0,0 +1,15 @@
+class_name KeybindPopup
+extends Control
+
+signal event_detected(event: InputEvent)
+
+var found_event: bool = false
+
+func _input(event: InputEvent) -> void:
+	if found_event:
+		return
+	if event is InputEventKey or event is InputEventMouseButton or event is InputEventJoypadButton:
+		get_viewport().set_input_as_handled()
+		found_event = true
+		event_detected.emit(event)
+		queue_free()