Add support for button entities (#2824)

esphome/components/restart/switch/restart_switch.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/switch/switch.h"
+
+namespace esphome {
+namespace restart {
+
+class RestartSwitch : public switch_::Switch, public Component {
+ public:
+  void dump_config() override;
+
+ protected:
+  void write_state(bool state) override;
+};
+
+}  // namespace restart
+}  // namespace esphome