chore: update docker layout

Dockerfiles in root gezet zodat ze ook aan bestanden daarin kunnen

frontend.Dockerfile

@@ -0,0 +1,13 @@
+# build stage
+FROM node:22 as build-stage
+WORKDIR /app
+COPY ./frontend/package*.json ./
+RUN npm install
+COPY ./frontend .
+RUN npm run build
+
+# production stage
+FROM nginx:stable as production-stage
+COPY --from=build-stage /app/dist /usr/share/nginx/html
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]