New homepage mvp

[maxelkins]

Summary

Branched from #6

Starts the implementation of new homepage design - copy and design feedback welcome.

• Adds "logo" (with accessible text)
• Changes h1 and subcopy
• Adds a "How does it work" section
• Refines some general styles

Smaller tweaks:

• Created more shared styles (inline code, headings, etc.)
• Formatting (Based off of Add formatting config #6)

Intentially left out of this PR

• Split up into pages rather than tabs
  • Remove/modify navigation as per design
• Add more homepage content such as command lists
• Further style refinement - better to do once demo styles are seperated

Screenshot

[maxelkins]

@grega should get this version in then iterate on the rest in a couple other PRs? Or would you rather wait and do in 1?

[grega]

@maxelkins Totally up to you, however you'd prefer to work.

The site doesn't get built until there's a new release of hdi (so that the site isn't ahead of any of the actually released features), so it won't get published to https://hdi.gregdev.com yet if merged to main (though I can always push a new release just to get the site built, if needed).

[maxelkins]

@grega I think if you are happy go ahead and merge this one and I'll follow up. Prefer to keep the PRs smaller.

[grega]

@maxelkins yep, done. Thanks for this!