extract buiild step to github runner

Dockerfile

@@ -1,18 +1,10 @@
-FROM node:lts-alpine AS builder
-WORKDIR /app
-
-COPY package*.json ./
-RUN npm ci
-
-COPY . .
-RUN npm run build
-
 FROM nginx:stable-alpine
 
 RUN rm -rf /usr/share/nginx/html/*
 
-COPY --from=builder /app/dist /usr/share/nginx/html
+COPY ./dist /usr/share/nginx/html
 
+# If you have a custom nginx config for Astro (SPAs/Routing), uncomment this:
 # COPY nginx.conf /etc/nginx/conf.d/default.conf
 
 EXPOSE 80