Possibility to make pin check methods public

[x29a]

Hi there and thanks for this great library!

Is there a reason why the pin check methods

espsoftwareserial/src/SoftwareSerial.h

Lines 234 to 236 in a97f09a

	static constexpr bool isValidGPIOpin(int8_t pin);
	static constexpr bool isValidRxGPIOpin(int8_t pin);
	static constexpr bool isValidTxGPIOpin(int8_t pin);

are in the private section of the class declaration?

If they were public, one could use the library to find appropriate pins, thanks to ESP32 pin multiplexing, this could be done during runtime. If course, there needs to be a valid device connected still ;)

At least it makes it easier to print out "yes, the pins you have configured are correct for this library".

[fanfanlatulipe26]

Have a look at : add "weak" attribute to function isValidGPIO , isValidRxGPIO , isValidTxGPIO #251
But is was closed
and also: Use GPIO2 as TX #261

[dok-net]

Implemented in d958f7b

[x29a]

@fanfanlatulipe26 thanks for your pointers, i did look at the other open and closed issues for discussion but didnt find anything about accessibility of those methods, i think your weak linkage issue is more about the possibility to override the methods.

@dok-net thanks for the quick implementation! i updated the readme to reflect the new method names in #274