Fixed typo in comments. (#5407)

A typographical error is corrected in the 2nd line of the comment. 
From = " This is un example howto use Touch Intrrerupts "
To = " This is an example of how to use Touch Intrrerupts "

libraries/ESP32/examples/Touch/TouchInterrupt/TouchInterrupt.ino

 /*
-This is un example howto use Touch Intrrerupts
+This is an example how to use Touch Intrrerupts
 The bigger the threshold, the more sensible is the touch
 */