Bind Home key to MOVE_HOME

On pressing Home key on the computer, move the cursor to the beginning
of the line instead of going back to the home screen.

<https://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME>
<https://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_MOVE_HOME>

Fixes (part of) <https://github.com/Genymobile/scrcpy/issues/555>.

app/src/main.c

@@ -105,7 +105,6 @@ static void usage(const char *arg0) {
         "        resize window to remove black borders\n"
         "\n"
         "    Ctrl+h\n"
-        "    Home\n"
         "    Middle-click\n"
         "        click on HOME\n"
         "\n"