## 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
function getElementTypeForFiber(fiber: Fiber): ElementType {
    const {type, tag} = fiber;
    switch (tag) {
      case ClassComponent:
      case IncompleteClassComponent:
        return ElementTypeClass;
      case FunctionComponent:
      case IndeterminateComponent:
        return ElementTypeFunction;
      case ForwardRef:
        return ElementTypeForwardRef;
      case HostRoot:
        return ElementTypeRoot;
      case HostComponent:
        return ElementTypeHostComponent;
      case HostPortal:
      case HostText:
      case Fragment:
        return ElementTypeOtherOrUnknown;
      case MemoComponent:
      case SimpleMemoComponent:
        return ElementTypeMemo;
      case SuspenseComponent:
        return ElementTypeSuspense;
      case SuspenseListComponent:
        return ElementTypeSuspenseList;
      default:
        const typeSymbol = getTypeSymbol(type);
        switch (typeSymbol) {
          case CONCURRENT_MODE_NUMBER: