codal_app/main: Initialise logo pin in capacitive touch mode.

Capacitive touch mode is more sensitive.  The other (edge connector) pins
are left in resistive touch mode by default, to match micro:bit v1.

Signed-off-by: Damien George <damien@micropython.org>

src/codal_app/main.cpp

@@ -75,6 +75,9 @@ int main() {
     uBit.audio.setSpeakerEnabled(true);
     uBit.audio.setPinEnabled(false);
 
+    // Initialise the logo pin in capacitive touch mode.
+    uBit.io.logo.isTouched(TouchMode::Capacitative);
+
     mp_main();
     return 0;
 }