docs(README.md): Mention RAISE_EXCEPTIONS

Author: PLNech

README.md

@@ -83,11 +83,12 @@ ALGOLIA = {
 }
 ```
 
-There are three optional settings:
+There are several optional settings:
 
 * `INDEX_PREFIX`: prefix all indexes. Use it to separate different applications, like `site1_Products` and `site2_Products`.
 * `INDEX_SUFFIX`: suffix all indexes. Use it to differentiate development and production environment, like `Location_dev` and `Location_prod`.
 * `AUTO_INDEXING`: automatically synchronize the models with Algolia (default to **True**).
+* `RAISE_EXCEPTIONS`: raise exceptions on network errors instead of logging them (default to **settings.DEBUG**).
 
 ## Quick Start