GitLab

* Adds HardwareSerial::setTxBufferSize()

* uartBegin def fix

* checks TXBufferSize  as defined in IDF

Makes sure that the buffer size will not cause a reset to the board.

* Removes double value in Rx/Tx Buffer Size 

Keeps Rx/Tx buffer size as set, not doubling it. It makes the process more clear.
Co-authored-by: Rodrigo Garcia <rodrigo.garcia@espressif.com>