Update README.md

README.md

@@ -551,17 +551,17 @@ that are _not_ under the base URL—such as pages—will not be validated.
 
 **A:** Add `additionalProperties: false` when [describing](https://swagger.io/docs/specification/data-models/keywords/) e.g a `requestBody` to ensure that additional properties are not allowed. For example:
 
-	```yaml
-	Pet:
-	  additionalProperties: false
-	  required:
-	    - name
-	  properties:
-	    name:
-	      type: string
-	    type:
-	      type: string
-	```
+  ```yaml
+  Pet:
+  additionalProperties: false
+  required:
+    - name
+  properties:
+    name:
+      type: string
+    type:
+      type: string
+  ```
 
 **Q:** Can I use `express-openapi-validator` with `swagger-ui-express`?