docs: reflow paragraph to satisfy prettier

Removing the duplicated word shortened a line, so prettier now wraps the
paragraph differently.

Signed-off-by: sweettypdevassy <sweettypdevassy@ibm.com>

Author: sweettypdevassy

docs/site/Testing-Your-Extensions.md

@@ -113,9 +113,9 @@ You can find an advanced example on testing controllers in
 The recommended usage of a decorator is to store metadata about a class or a
 class method. The decorator implementation usually provides a function to
 retrieve the related metadata based on the class name and method name. For a
-unit test for a decorator, it is important to test that it stores and
-retrieves the correct metadata. _The retrieval gets tested as a result of
-validating whether the metadata was stored or not._
+unit test for a decorator, it is important to test that it stores and retrieves
+the correct metadata. _The retrieval gets tested as a result of validating
+whether the metadata was stored or not._
 
 Following is an example for testing a decorator: