added basic routes

Author: Jaime Salas Zancada

01-contenedores/lemoncode-challenge/node-stack/backend/.env.template

@@ -1 +1,3 @@
-DATABASE_URL=mongodb://localhost:27017
+DATABASE_URL=
+HOST=
+PORT=

01-contenedores/lemoncode-challenge/node-stack/backend/README.md

@@ -0,0 +1,32 @@
+# backend
+
+## Running Locally
+
+This application has a direct dependency with mongo. To running locally by default the application expects that mongo is listening on port 27017.
+
+It's going to connect with `TopicstoreDb` on mongo server, and it's foing to interact with `Topics` collection.
+
+It's important to mention, that the default connection string is `mongodb://localhost:27017`, we can override it, using env variables.
+
+The following are environment variables that we can set up:
+
+```ini
+DATABASE_URL=
+HOST=
+PORT=
+```
+
+Notice that `HOST` is set by default on `localhost` and `PORT` on `5000`. These are the settings to stablish where the HTTP application is listening. You don't need to change it.
+
+With the database running you can check the appliaction by running:
+
+```bash
+npm start
+```
+
+And then call it with;
+
+```bash
+curl http://localhost:5000/api/topics
+```
+