Update dependencies to fix broken NPM installation and running

[leandrumartin]

Running npm install was not working due to outdated and deprecated dependencies. Specifically, the canvas dependency was causing it to fail (attempting the command with only that dependency removed succeeded). I updated the required version to the minimum required version to get the command to work.

Once npm install ran, npm start was failing to compile the project. The reason given by the errors was that PostCSS 8 was required. Running npm ls postcss revealed that it was a dependency of Docusaurus, so I also upgraded the required Docusaurus version to the minimum that would allow it to run.

Now, both npm install and npm start work.

[kungfuchicken]

When I ran an npm install && npm start the site stopped working locally for me. It builds, but never loads in a browser. This is probably something locally for me. It might even be a browser cache issue. I'll look into it by tomorrow.

One nice thing, though. Somehow it's now respecting my browser preference (opening in Firefox instead of Chrome).

[leandrumartin]

It might be local to you. I've tested this on two devices and it works well on both.