Update POST request to use valid JSON (#7)

Author: spiffcs

text/1.md

@@ -229,7 +229,7 @@ We have a couple options if we want to run this query and get the data back from
 
 ```sh
 $ curl -X POST -H "Content-Type:application/json" \
->     -d '{user(id: "123"){_id, username}}' \
+>     -d '{"query": "{user(id: \"123\"){_id username}}"}' \`
 >     http://localhost:3000/graphql
 {"data":{"user":{"_id":"123","username":"jeresig"}}}
 ```
@@ -240,7 +240,7 @@ What happens when we attempt to query for a user that doesn’t exist? Does it r
 
 ```sh
 $ curl -X POST -H "Content-Type:application/json" \
->     -d '{user(id: "abc"){_id, username}}' \
+>     -d '{"query": "{user(id: \"123\"){_id username}}"}' \
 >     http://localhost:3000/graphql
 {"data":{"user":null}}
 ```