ADD: heltec wsl v3 pinout information (#7883)

* ADD: heltec wsl v3 pinout information

Information based on website and s3 manual

* UPD: heltec wsl v3 pinout

ADD: proper versioning to the definition (added v3)
FIX: TX/RX inversion.
UPD: analog pins to be defined as a consecutive numeration.

* UPD: heltec wsl v3 pinout 

FIX: number of digital pins.

variants/heltec_wireless_stick_lite_v3/pins_arduino.h

+#ifndef Pins_Arduino_h
+#define Pins_Arduino_h
+
+#include <stdint.h>
+
+#define Wireless_Stick_Lite_V3 true
+#define DISPLAY_HEIGHT 0
+#define DISPLAY_WIDTH  0
+
+#define EXTERNAL_NUM_INTERRUPTS 16
+#define NUM_DIGITAL_PINS        20
+#define NUM_ANALOG_INPUTS       15
+
+#define analogInputToDigitalPin(p)  (((p)<20)?(analogChannelToDigitalPin(p)):-1)
+#define digitalPinToInterrupt(p)    (((p)<40)?(p):-1)
+#define digitalPinHasPWM(p)         (p < 34)
+
+static const uint8_t LED_BUILTIN = 35;
+#define BUILTIN_LED  LED_BUILTIN // backward compatibility
+#define LED_BUILTIN LED_BUILTIN
+
+static const uint8_t TX = 43;
+static const uint8_t RX = 44;
+
+static const uint8_t SDA = 2;
+static const uint8_t SCL = 3;
+
+static const uint8_t SS    = 34;
+static const uint8_t MOSI  = 35;
+static const uint8_t SCK   = 36;
+static const uint8_t MISO  = 37;
+
+static const uint8_t A0 = 1;
+static const uint8_t A1 = 2;
+static const uint8_t A2 = 3;
+static const uint8_t A3 = 4;
+static const uint8_t A4 = 5;
+static const uint8_t A5 = 6;
+static const uint8_t A6 = 7;
+static const uint8_t A7 = 12;
+static const uint8_t A8 = 14;
+static const uint8_t A9 = 15;
+static const uint8_t A10 = 16;
+static const uint8_t A11 = 17;
+static const uint8_t A12 = 18;
+static const uint8_t A13 = 19;
+static const uint8_t A14 = 20;
+
+static const uint8_t T0 = 1;
+static const uint8_t T1 = 2;
+static const uint8_t T2 = 3;
+static const uint8_t T3 = 4;
+static const uint8_t T4 = 5;
+static const uint8_t T5 = 6;
+static const uint8_t T6 = 7;
+
+static const uint8_t Vext = 36;
+static const uint8_t LED  = 35;
+
+#endif /* Pins_Arduino_h */