Minimize bundle size and further reduce HTTP requests

[runemadsen]

This PR does two things:

Minize bundle size

• Remove inline CSS It minimizes the bundle size by removing the inline CSS on all pages, relying only on the external CSS files. In theory, this makes the site a bit slower to render, but it really doesn't seem like a problem from my tests. The change results in the /reference folder going from 100MB to 30MB in uncompressed size 👀 .
• Remove p5 as dependency. The p5.js library is 1.8MB in uncompressed size, which made it the by far largest JS to load on the website. This PR removes the p5 import in favor of using CDNJS. We need to revisit this for the offline version since the interactive examples won't work without an internet connection, but it will make a big difference with Cloudfront since it's the 3rd most loaded JS file in terms of size.
• Remove luxonas dependency. We were relying on luxon and its 300kb for a single line of code. This removes the lib to rely on toLocaleString instead.

Further reduce HTTP requests

• Adding to the work already done, this PR reduces the number of HTTP requests by minimizing the use of useStatucQuery in two main components: HeadMatter and Layout.