## 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
internalInstance: InternalInstance,
    id: number,
    parentID: number,
  ) {
    const isRoot = parentID === 0;
    if (__DEBUG__) {
      console.log(
        '%crecordMount()',
        'color: green; font-weight: bold;',
        id,
        getData(internalInstance).displayName,
      );
    }
    if (isRoot) {
      
      const hasOwnerMetadata =
        internalInstance._currentElement != null &&
        internalInstance._currentElement._owner != null;
      pushOperation(TREE_OPERATION_ADD);
      pushOperation(id);
      pushOperation(ElementTypeRoot);
      pushOperation(0); 
      pushOperation(hasOwnerMetadata ? 1 : 0);
    } else {
      const type = getElementType(internalInstance);
      const {displayName, key} = getData(internalInstance);