enabled delete key for alternatives

app/ui/main.glade

@@ -73,6 +73,7 @@ Author: Dmitriy Yefremov
         <property name="can-focus">False</property>
         <property name="label" translatable="yes">Remove</property>
         <signal name="activate" handler="on_delete" object="alt_tree_view" swapped="no"/>
+        <accelerator key="Delete" signal="activate"/>
       </object>
     </child>
   </object>

app/ui/main.py

@@ -4526,6 +4526,8 @@ class Application(Gtk.Application):
 
         if ctrl and key == KeyboardKey.V:
             self.alt_paste()
+        elif key == KeyboardKey.DELETE:
+            self.on_delete(view)
 
     def alt_paste(self):
         srv = self._services.get(self._alt_model.get_value(self._alt_model.get_iter_first(), Column.ALT_ID), None)