## 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
2 + // [rendererID, rootFiberID]
      // How big is the string table?
      1 + // [stringTableLength]
        // Then goes the actual string table.
        pendingStringTableLength +
        // All unmounts are batched in a single message.
        // [TREE_OPERATION_REMOVE, removedIDLength, ...ids]
        (numUnmountIDs > 0 ? 2 + numUnmountIDs : 0) +
        
        pendingOperations.length,
    );
    
    
    
    let i = 0;
    operations[i++] = rendererID;
    operations[i++] = rootID;
    
    
    operations[i++] = pendingStringTableLength;
    pendingStringTable.forEach((value, key) => {
      operations[i++] = key.length;
      const encodedKey = utfEncodeString(key);
      for (let j = 0; j < encodedKey.length; j++) {
        operations[i + j] = encodedKey[j];
      }
      i += key.length;
    });
    if (numUnmountIDs > 0) {