chore: rename website-astro to website, update gitignore

- Rename website-astro/ to website/
- Add website/dist/ and website/.astro/ to gitignore
- Update generate-website-data.mjs output path

website/astro.config.mjs

@@ -0,0 +1,14 @@
+import { defineConfig } from 'astro/config';
+import sitemap from '@astrojs/sitemap';
+
+// https://astro.build/config
+export default defineConfig({
+  site: 'https://github.github.io',
+  base: '/awesome-copilot/',
+  output: 'static',
+  integrations: [sitemap()],
+  build: {
+    assets: 'assets',
+  },
+  trailingSlash: 'always',
+});