## The current behavior

The full value of the `key` is very difficult / impossible to find and use in the interface of the React Devtools.

![Kapture 2020-04-22 at 11 47 47](https://user-images.githubusercontent.com/1935696/79997715-25222680-84ba-11ea-97ba-51f1679a8c91.gif)

Only managed to find it by accident :(

## The expected behavior

The `key` is visible in the props list to the right.

### Detailed Proposal

As mentioned below in https://github.com/facebook/react/issues/18702#issuecomment-617924196

Add a light divider and new section in the props panel to the right.

Potentially also add a question mark that shows an explanation about the fact that things in this section are not really props.

Ref (Original implementation): https://github.com/facebook/react-devtools/pull/328
/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */
import * as React from 'react';
import {
  createContext,
  useCallback,
  useContext,
  useEffect,
  useMemo,
  useRef,
  useState,
} from 'react';
import {unstable_batchedUpdates as batchedUpdates} from 'react-dom';
import {createResource} from '../../cache';
import {BridgeContext, StoreContext} from '../context';
import {hydrate, fillInPath} from 'react-devtools-shared/src/hydration';
import {TreeStateContext} from './TreeContext';
import {separateDisplayNameAndHOCs} from 'react-devtools-shared/src/utils';
import type {
  InspectedElement as InspectedElementBackend,
  InspectedElementPayload,
} from 'react-devtools-shared/src/backend/types';
import type {
  DehydratedData,