## 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
}
        if (!didFindChild) {
           S
          child = parentB.child;
          while (child) {
            if (child === a) {
              didFindChild = true;
              a = parentB;
              b = parentA;
              break;
            }
            if (child === b) {
              didFindChild = true;
              b = parentB;
              a = parentA;
              break;
            }
            child = child.sibling;
          }
          if (!didFindChild) {
            throw Error(
              'Child was not found in either parent set. This indicates a bug ' +
                'in React related to the return pointer. Please file an issue.',
            );
          }
        }
      }
      if (a.alternate !== b) {
        throw Error(
          "Return fibers should always be each others' alternates. " +