docs: convert `print` statement to function (#988)

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Fixes #987 🦕

docs/start.md

diff --git a/docs/start.md b/docs/start.md
index 4caf706..2db95fa 100644
--- a/docs/start.md
+++ b/docs/start.md
@@ -98,7 +98,7 @@
 ```python
 import json
 ...
-print json.dumps(response, sort_keys=True, indent=4)
+print(json.dumps(response, sort_keys=True, indent=4))
 ```
 
 For example, if the printed JSON is the following: