upgrade

Upgraded to most recent version of Docusaurus to avoid warning - failed, warning still present. The use of componentWillMount warned about is buried in Docusaurus code that we can't directly modify.

# Getting following react warning:
react-dom.development.js?61bb:88 Warning: componentWillMount has been renamed, and is not recommended for use. See https://fb.me/react-unsafe-component-lifecycles for details.
* Move code with side effects to componentDidMount, and set initial state in the constructor.
* Rename componentWillMount to UNSAFE_componentWillMount to suppress this warning in non-strict mode. In React 17.x, only the UNSAFE_ name will work. To rename all deprecated lifecycles to their new names, you can run `npx react-codemod rename-unsafe-lifecycles` in your project source folder.
Please update the following components: LoadableComponent
# Tried upgrade to avoid the warning
yarn upgrade
success Saved 863 new dependencies.
info Direct dependencies
โ”œโ”€ @docusaurus/preset-classic@2.0.0-alpha.61
โ”œโ”€ react-dom@16.13.1
โ””โ”€ react@16.13.1
# Warning still present
#