update deployment workflow

- Deploy to CF Pages on pushes to 'prod' branch
- Add a script to push main to prod

package.json

@@ -29,7 +29,8 @@
     "preview": "astro preview",
     "astro": "astro",
     "generate:og": "tsx scripts/generate-og-image.ts",
-    "prettier": "prettier --write **/*.{ts,tsx,css,astro} --ignore-path .gitignore"
+    "prettier": "prettier --write **/*.{ts,tsx,css,astro} --ignore-path .gitignore",
+    "deploy": "git push origin main:prod"
   },
   "dependencies": {
     "@astrojs/check": "^0.9.8",