Dark theme option for the Miden official website

A dark theme option for the Miden official website would significantly improve readability, particularly for blog posts. The current white background becomes uncomfortable during extended reading sessions, especially given the length of the content.

The issue is for the Miden official website, likely a static site. First, locate the website's repository (not this feedback repo) and its styling system (CSS, a framework like Tailwind). Look for existing theme variables or a stylesheet. Adding a dark theme involves creating a color scheme and a toggle, possibly using CSS custom properties. Check for any existing JavaScript for theme switching. 'Done' means the site has a functional dark mode toggle that applies to all pages, especially blog posts.

索引モデルが issue の本文から書いたものです。