Add blog via Astro content collections

Introduce blog support: content collection schema, listing and post
routes, and a sample Markdown post. Update docs and TODO; add blog
assets dir and adjust color variables in docs. Also set
absolute_redirect off in nginx.conf for container routing.

README.md

@@ -9,10 +9,11 @@ Cozy Den is a warm, self-hosted corner of the internet. This landing page repres
 ## Features
 
 - ☕ Cozy, warm aesthetic with hidden den theme
-- 🎨 Custom color palette inspired by coffee and warmth
+- 🎨 Catppuccin Mocha color palette
 - 📱 Responsive design
 - ⚡ Built with Astro for blazing fast performance
 - 🐳 Docker support for easy deployment
+- 📝 Blog powered by Astro Content Collections (hardcoded Markdown, no CMS)
 
 ## Setup
 
@@ -55,7 +56,7 @@ docker build -t cozy-den .
 ### Running the Container
 
 ```bash
-docker run -d -p 3000:3000 --name cozy-den cozy-den
+docker run -d -p 3000:80 --name cozy-den cozy-den
 ```
 
 Or with docker-compose:
@@ -84,6 +85,8 @@ The site is built to be easily customizable:
 - **Colors**: Edit the CSS variables in `src/layouts/BaseLayout.astro`
 - **Content**: Update sections in `src/pages/index.astro`
 - **Favicon**: Replace `public/favicon.svg`
+- **Blog posts**: Add `.md` files to `src/content/blog/` — they appear automatically at `/blog`
+- **Blog images**: Place images in `public/blog/<post-slug>/` and reference with `/blog/<post-slug>/image.jpg`
 
 ## Technology Stack