Added Astro.js guide

examples/docker/astro.dockerfile

@@ -0,0 +1,9 @@
+FROM node:lts-alpine AS build
+WORKDIR /app
+COPY . .
+RUN npm i
+RUN npm run build
+
+FROM httpd:2.4 AS runtime
+COPY --from=build /app/dist /usr/local/apache2/htdocs/
+EXPOSE 80