fix for knob press

[Rocketct]

this change with the fps fix resolve the #20 issue, call the update before the get or is pressed allows to avoid false negative reading from the i2s bus

[leonardocavagnis]

@Rocketct LGTM :)

Please, could you add update() function to the api.md document?
https://github.com/arduino-libraries/Modulino/blob/main/docs/api.md#modulinoknob

[sebromero]

I suggest to move the whole API documentation to the header file and use the GH action that I created to render the API docs automatically: https://github.com/arduino/render-docs-github-action

[Rocketct]

@leonardocavagnis done added last fix you can test on yours side and then merge?