Merge pull request #2357 from arduino/benjamindannegard/fix-nano-every-clock-speed

[PXCT-368] Fixed nano every clock speed info

Author: BenjaminDannegard

content/hardware/03.nano/boards/nano-every/tech-specs.yml

@@ -17,7 +17,7 @@ Power:
   Input voltage (nominal): 7-21V
   DC Current per I/O Pin: 15 mA
 Clock speed:
-  Processor: ATMega4809 16 MHz
+  Processor: ATMega4809 20 MHz
 Memory:
   ATmega328P: 6KB SRAM, 48KB flash 256 byte EEPROM
 Dimensions: