chore: backend docker setup

.dockerignore en .dockerfile van de backend ingesteld

backend/.dockerignore

@@ -0,0 +1,7 @@
+**/node_modules/
+**/dist
+.git
+npm-debug.log
+.coverage
+.coverage.*
+.env

backend/backend.dockerfile

@@ -0,0 +1,14 @@
+FROM node:22
+
+WORKDIR /app
+
+COPY ./package*.json ./
+
+RUN npm install
+
+COPY . .
+
+EXPOSE 80
+EXPOSE 443
+
+CMD ["npm", "start"]