Added example compose files for databases

src/skeletons/composes/mariadb.yaml

@@ -0,0 +1,12 @@
+version: '3.1'
+
+services:
+    db:
+        image: mariadb
+        restart: always
+        environment:
+            MARIADB_ROOT_PASSWORD: root
+            MARIADB_USER: nork
+            MARIADB_PASSWORD: nork
+		volumes:
+			./db-data:/var/lib/mysql

src/skeletons/composes/mongodb.yaml

@@ -0,0 +1,20 @@
+# Use root/example as user/password credentials
+version: '3.1'
+
+services:
+    mongo:
+        image: mongo
+        restart: always
+        environment:
+            MONGO_INITDB_ROOT_USERNAME: root
+            MONGO_INITDB_ROOT_PASSWORD: root
+
+    mongo-express:
+        image: mongo-express
+        restart: always
+        ports:
+            - 8081:8081
+        environment:
+            ME_CONFIG_MONGODB_ADMINUSERNAME: root
+            ME_CONFIG_MONGODB_ADMINPASSWORD: root
+            ME_CONFIG_MONGODB_URL: mongodb://root:example@mongo:27017/