docs: datetime year autofill disable

[ar-to]

Felt like a bug until I tracked it down to an option to disable. Consider adding this to the docs in the description so others know what options are available.

Version of this lib used at the time: "use-mask-input": "^3.3.6",

Options from this lib

use-mask-input/src/inputmask.types.ts

Line 547 in 3d2cc2d

prefillYear?: boolean | undefined;

Options from inputmask:

• options seem to match but did not match them all so you can confirm.
• Version used here
  https://github.com/eduardoborges/use-mask-input/blob/3d2cc2dce950f6e5ed7eed7bae08eb10e76d23b8/package.json#L39C6-L39C15
• demo https://robinherbots.github.io/Inputmask/#/demo

For this particular autofill fix I found it via RobinHerbots/Inputmask#2266 (comment), and via the prefillYea option at https://robinherbots.github.io/Inputmask/#/documentation/datetime#prefillyear.

Snippet:

      options: {
        inputFormat: 'mm/dd/yyyy',
        prefillYear: false,
      },

prevents the autofill for the year which may feel like unexpected behavior in some cases, e.g. data of birth which should not autofill to current year.