trivial - remove duplicate word from documentation
@@ -309,7 +309,7 @@ indexNodeName
By default, the cost of using this index is calculated follows: For each query,
the overhead is one operation. For each entry in the index, the cost is one.
The following only applies to `compatVersion` 2 only:
-To use use a lower or higher cost, you can set the following optional properties
+To use a lower or higher cost, you can set the following optional properties
in the index definition:
- costPerExecution (Double) = 1.0
