Fix missed heading format

Author: seanonthenet

README.md

@@ -24,7 +24,7 @@ Simply run Zeus in your terminal to output your types file based on your graphql
 
 ![](images/zeus-bash-command.png)
 
-##Usage Example
+## Usage Example
 Example using a generated `chain` client. Queries, mutations and subscriptions are now type-safe in arguments, field selections and response types.
 
 ![](images/example.png)