techo: initial support of new companion ui

variants/techo/platformio.ini

@@ -73,6 +73,7 @@ build_src_filter = ${LilyGo_Techo.build_src_filter}
   +<helpers/nrf52/TechoBoard.cpp>
   +<helpers/nrf52/SerialBLEInterface.cpp>
   +<helpers/ui/GxEPDDisplay.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
   +<../examples/companion_radio>
 lib_deps =
   ${LilyGo_Techo.lib_deps}