Handle debounce in I2CKeypad_interrupts_1 example

[rafork]

Hi, The example code in I2CKeypad_interrupts_1.ino has a potential bug. The loop() function doesn't handle the case where getKey() returns I2C_KEYPAD_THRESHOLD (255). Instead, it uses the number 255 as an index into an array of 19 bytes. That's an invalid memory access. To fix it, the following should be added after the call to getKey().

if (index == I2C_KEYPAD_THRESHOLD)
    return;

Perhaps it's not really a bug since it doesn't call the new setDebounceThreshold() method, but this pull request does that as well. It might not strictly be necessary for this example, but I think it makes it a better example.

[RobTillaart]

good catch,
The object keypad should be KeyPad, as the example doesn't compile anymore.

[rafork]

Oops. I've fixed that (keyPad, not KeyPad).

[RobTillaart]

@rafork

There is another one to fix

Compilation failure details... 
    compiler_err... 
        /home/runner/work/I2CKeyPad/I2CKeyPad/examples/I2CKeypad_interrupts_1/I2CKeypad_interrupts_1.ino: In function 'void setup()':
        /home/runner/work/I2CKeyPad/I2CKeyPad/examples/I2CKeypad_interrupts_1/I2CKeypad_interrupts_1.ino:83:3: error: 'keypad' was not declared in this scope; did you mean 'keyPad'?
           83 |   keypad.setDebounceThreshold(50);
              |   ^~~~~~
              |   keyPad
    ...compiler_err         

did you push the fix to the rafork:interrupt_handle_debounce branch

[rafork]

Oops. It's there now.

[RobTillaart]

@rafork
Merged into master,
Thanks again for the fix, appreciated