[material-ui][docs][TextField] Update react-number-format integration demo

[rswlkr]

react-number-format has a customInput prop that allows passing materialui components. A custom implementation of the input component is therefore not required and the docs/examples should be updated to reflect this.

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

[eps1lon]

Could you include an example that uses customInput over our current solution?

[rswlkr]

          <NumberFormat
            customInput={TextField}
            thousandSeparator={true}
            prefix={'£'}
            id='minValue'
            label='Minimum Value'
            onChange={handleChange}
            value={minValue}
            className={classes.formControl}
            inputProps={{
              name: 'minValue'
            }}
          />

https://github.com/s-yadav/react-number-format#custom-inputs

[oliviertassinari]

I wonder about the best option we have here. In which order should we compose the two components? NumberFormat > TextField as in the above example requires less code. I wonder about the implication it can have with the MaskedInput example. I also wonder about the forms libraries integrations.

[bsell93]

The codebase I'm working on was having issues with using the recommended way in the MUI docs. Ended up using the above suggested method with NumberFormat and customInput={TextField} prop and that fixed the issues we were having.

Unfortunately we were not able to reproduce the issue in a codesandbox with our setup, so hard saying what it was about the MUI-suggested way but something was definitely messing it up from within the TextField component.