Add delay before initialising DHT22

[cgmcintyr]

• Fixes Waterelf32 startPeripherals not detecting DHT22 #15
• Defines BUILTIN_LED as pin 13

[layerzerolabs]

I see BUILTIN_LED defined in .../Arduino/hardware/espressif/esp32/variants/feather_esp32/pins_arduino.h
static const uint8_t LED_BUILTIN = 13;
#define BUILTIN_LED LED_BUILTIN // backward compatibility
I don't understand the value of (re?)defining this in the sketch?

[cgmcintyr]

Sorry, this may be to do with not including the Arduino/hardware/espressif/esp32/variants/feather_esp32/pins_arduino.h, I'll be sure to remove the definition of BUILTIN_LED from the pull request.

[layerzerolabs]

Ah yes, I remember you saying you were also using the expressif IDF - fundamentally better I'm sure but for us the main advantage of the arduino IDE is that novices can hack our stuff, widening up participation...

[hamishcunningham]

Happy to merge but pending discussion on #15 ...?