feat(main): add shortcuts to open or create a new journal

src/main.py

@@ -55,6 +55,16 @@ class Application(Gtk.Application):
         self.add_action(save_as_action)
         self.set_accels_for_action('app.save_as', ['<Ctrl><Shift>S'])
 
+        new_action = Gio.SimpleAction.new('new', None)
+        new_action.connect('activate', self._new)
+        self.add_action(new_action)
+        self.set_accels_for_action('app.new', ['<Ctrl>N'])
+
+        open_action = Gio.SimpleAction.new('open', None)
+        open_action.connect('activate', self._open)
+        self.add_action(open_action)
+        self.set_accels_for_action('app.open', ['<Ctrl>O'])
+
     def _quit(self, action, param):
         win = self.props.active_window
         win.close()
@@ -67,6 +77,14 @@ class Application(Gtk.Application):
         win = self.props.active_window
         win.save_file_as()
 
+    def _new(self, action, param):
+        win = self.props.active_window
+        win.new_journal()
+
+    def _open(self, action, param):
+        win = self.props.active_window
+        win.open_file()
+
 
 def main(version):
     app = Application()