Convert Blog to Pure Markdown While Keeping SvelteKit for the Rest of the Site

[grmbyrn]

Currently, our blog uses Markdown with MDsveX, allowing for Svelte components inside posts. This issue tracks the whether we should transition the blog to pure Markdown, separating content management from the SvelteKit framework while keeping the rest of the website in SvelteKit. After discussing with @matfantinel, the goal is to improve portability, simplify content creation, and ensure long-term flexibility.

Tasks

• Remove MDsveX dependencies.
• Implement a pure Markdown-based blog rendering system.
• Set up a Markdown parser (e.g., svelte-markdown) with support for custom elements.
• Ensure blog data can still be queried and displayed across the site.