Highlight.js version 9 is deprecated

https://github.com/casesandberg/react-color/blob/bc9a0e1dc5d11b06c511a8e02a95bd85c7129f4b/package.json#L79

From the console:
```
Verion 9 of Highlight.js has reached EOL. It will no longer
be supported or receive security updates in the future.
Please upgrade to version 10 or encourage your indirect
dependencies to do so.

For more info:

https://github.com/highlightjs/highlight.js/issues/2877
https://github.com/highlightjs/highlight.js/blob/master/VERSION_10_UPGRADE.md
```

Start at the package.json dependency entry linked in the issue and review the Highlight.js version 10 upgrade guide. Update the dependency from version 9 to a supported version, then verify the project still installs and its existing checks pass without the deprecation warning.

Written by the indexing model from the issue text.