Add README with build instructions

Author: pelle

README.md

@@ -0,0 +1,22 @@
+# Website
+
+This repository contains the source code for a static site built with [Lume](https://lume.land/), a Deno-based site generator.
+
+## Prerequisites
+
+- **Deno**: Install Deno (the workflow uses version 2.2.3).
+- **Node.js**: Required for Tailwind CSS processing (Node 18+ recommended).
+- **Tailwind CSS**: Handled automatically by the build tasks.
+
+## Development
+
+Build the site locally or serve it for development using Deno tasks defined in `deno.json`:
+
+```bash
+deno task build   # Build the site into the `_site` directory
+deno task serve   # Start a local server and watch for changes
+```
+
+## Deployment
+
+The site is deployed to **GitHub Pages** using the workflow in `.github/workflows/main.yml`. On pushes to the `main` branch, the workflow builds the site and uploads the `_site` directory to GitHub Pages.