MUI pickers version 6 and some more improvements

Breaking change due to new version of Pickers.

Upgrade to https://next.mui.com/x/migration/migration-pickers-v5/

Steps to upgrade:

• @mui/x-date-pickers => >=6

The component signature did not change

fixes #144

Add readonly prop to DatePicker and DateTimePicker

New prop is available to disable keyboard input:

<DatePickerElement name="date" textReadOnly/>

https://react-hook-form-material-ui.vercel.app/?path=/story/datepickerelement--disable-text-input
https://react-hook-form-material-ui.vercel.app/?path=/story/datetimepickerelement--disable-text-input

Add DateTimePicker

Add Datetimepicker

closes #90

Support small prop on MultiSelectElement

As the title say this is a minor bugfix for MultiSelectElement to support the small prop

New Component

New component ToggleButtonGroupElement

Check out the API:
https://react-hook-form-material-ui.vercel.app/?path=/story/togglebuttongroupelement--basic

Restructure Repo as Monorepo and re-export react-hook-form API

Due to context issues this release got refactored to a monorepo and the NextJS and Storybook examples are now using the compiled version of the library.

Beside that the API of react-hook-form is getting re-exported so the context of useWatch can be defined inside of NextJS.
https://github.com/dohomi/react-hook-form-mui/blob/master/apps/nextjs/src/pages/withSub.tsx#L5

Fixes #89

Minor fix for onChange TextFieldElement

Patches

• Propagate onChange for TextFieldElement closes #52: b585135

New DateTimePickerElement

Add new component DateTimePickerElement

For the use of the new element checkout the docs:
https://react-hook-form-material-ui.vercel.app/?path=/story/datetimepickerelement--basic

Thanks to @Morriz for his contribution.

• Create DateTimePickerElement.tsx: e889050
• Update index.ts: f7057d4
• Merge pull request #90 from Morriz/master: b5a3d39
• Add stories for DateTimePickerElement: 9edb9f4

Add example for month picker

Small fix on Multi-Select to support grid layout

Add example how a UI of a month picker could look like
Multi-Select:
https://react-hook-form-material-ui.vercel.app/?path=/story/multiselectelement--month-picker
Select:
https://react-hook-form-material-ui.vercel.app/?path=/story/selectelement--month-picker

• Add example for month picker: c67b8ff

Add Slider Element

New Component SliderElement

For use check https://react-hook-form-material-ui.vercel.app/?path=/story/slider-element--basic

• New SliderElement added: d0e6146
• Merge pull request #88 from jacokok/slider: f557db0
• Add slider element: 369d0e6