docs/deployment.yml : add setting environment variables (#369)

Author: gosuri

_docs/deployment.yml

@@ -42,6 +42,8 @@ services:
 
   web:
     image: foo:latest
+    env:
+      "API_KEY":"996fb92427ae41e4649b934ca495991b785"
     port: 80
     depends-on:
       - service: db-pool