use `useImperativeHandle` to share Refs

Description:

This PR adds an enhancement to the React Hook Form documentation by demonstrating how to share a ref using the useImperativeHandle hook. The shared ref is used to clear the input value when a user clicks on a "clear" button.

Changes Made:

Added a code snippet in both TypeScript and JavaScript that showcases the usage of useImperativeHandle to share a ref.
Created a functional component (App) that utilizes useForm from react-hook-form.
Created a ref using useRef to reference the input element.
Defined an onSubmit function to handle the form submission.
Extracted the ref and other properties from the register function for the "firstName" input field.
Implemented an onClick function that clears the value of the input element when the "clear" button is clicked.
Used useImperativeHandle to share the ref with the parent or other components.
Rendered the form, input field, and buttons, passing the necessary props.

Testing Done:

Tested the code locally to ensure the "clear" button successfully clears the input value.
Verified that the form submission and console logging of the form data work as expected.
React Hook Form Playground (forked) - CodeSandbox

react-hook-form / documentation

use `useImperativeHandle` to share Refs #1014