add minikube deployment/service script for backend

minikube-prod/backend.yaml

+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: backend-deployment
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: backend
+  template:
+    metadata:
+      labels:
+        app: backend
+    spec:
+      containers:
+        - name: backend-container
+          image: backend-image
+          ports:
+            - containerPort: 9876
+          env:
+            - name: MONGO_USER
+              value: tododbuser
+            - name: MONGO_PASSWORD
+              value: tododbadminpassword
+            - name: MONGO_HOST
+              value: mongodb-servicevice in Kubernetes.
+            - name: MONGO_PORT
+              value: "27017"
+            - name: MONGO_DB
+              value: todo
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: backend-service
+spec:
+  selector:
+    app: backend
+  ports:
+    - protocol: TCP
+      port: 80
+      targetPort: 9876
+  type: ClusterIP