Website: improve homepage onboarding and download flow

[tritao]

Refresh the FreeCAD Website homepage and download flow to make the product value, onboarding paths, and latest stable release easier to understand and act on.

What changed

• Added a clearer homepage hero with:
  • Versioned latest-release download CTA
  • Release notes link
  • Platform and open-source trust signals
  • Technical visual pattern with light/dark mode support
• Added three onboarding paths for new visitors.
• Consolidated and clarified the “Why FreeCAD?” content.
• Added workflow cards linked to relevant feature sections.
• Improved homepage spacing, responsive behavior, and visual hierarchy.
• Updated the download page with:
  • Clear “Download FreeCAD” heading
  • Latest stable release metadata
  • Release notes link
  • Platform-specific download cards
  • Automatic platform recommendation
  • Improved mobile stacking and button layout

I'm not particularly happy with the end-result here, I think it can be improved a lot both visually and content-wise.

What do you think @marcuspollio?

Desktop:

Mobile:

[github-actions]

PR #50 preview:

https://FreeCAD.github.io/Website/pr-50/

[marcuspollio]

Hi @tritao
Thanks for your contribution!

There are some nice ideas here!
However, this PR touches several different areas, making the design and implementation review a bit tricky, specially as I'm also trying to sort out how to best integrate @maxwxyz changes, some of which overlap.

So in order to ease the review and integration process, could you please split (different PRs) this into:

1. Donate FAQ, this one is very small and can be merged right after a quick check.

2. The two new shortcodes and associated assets (CSS, JS) if any. As of now, their logic and code is pretty bad. You can do better, I know! 😆 Please look at the official Hugo docs. Feel free to ask for specific questions or guidance. The implementation of workflow one is particularly ugly. We could maybe have a simpler card shortcode instead, that builds on the existing main/card.html template (to be refactored a bit) and just passes custom link, thumbnail, text (title, description), and "link text" (i.e. "explore") at the bottom? Also I am not sure we need to add the id attribute to the block shortcode, can you explain its use?

3. Homepage stuff:

• its content file (_index.md)
• changes to home.html template
• maybe we can create a new home.css (to be imported in main.css) with homepage-specific style. The stylesheets are already too messy, better not increase entropy even more 😁
• other changes.

4. Later, download and release stuff, once the builds data and workflow is sorted out (Max's PR).

How does that sound?

Please, do not add unrelated changes (e.g. page head, custom params, resources processing, etc), specially without any explanation. Also please disclose any use of AI, this repo is part of the FreeCAD org so same guidelines apply.
TIA!