docs: Use free-tier instance size

website/source/docs/templates/introduction.html.markdown

@@ -54,7 +54,7 @@ missing valid AWS access keys. Otherwise, it would work properly with
       "secret_key": "...",
       "region": "us-east-1",
       "source_ami": "ami-de0d9eb7",
-      "instance_type": "m1.small",
+      "instance_type": "t1.micro",
       "ssh_username": "ubuntu",
       "ami_name": "packer {{.CreateTime}}"
     }