Create buttons module

Temporarily just logging button presses, as alarms module doesn't yet
exist.

main/CMakeLists.txt

@@ -1,5 +1,5 @@
 idf_component_register(
   SRCS "main.c"
   INCLUDE_DIRS "."
-  REQUIRES console_wrapper display settings sound time wifi
+  REQUIRES buttons console_wrapper display settings sound time wifi
 )

main/main.c

@@ -3,6 +3,7 @@
  * Copyright (c) Camden Dixie O'Brien
  */
 
+#include "buttons.h"
 #include "console.h"
 #include "display.h"
 #include "settings.h"
@@ -18,4 +19,5 @@ void app_main(void)
 	wifi_init();
 	time_manager_init();
 	sound_init();
+	buttons_init();
 }