Provides a more specific example header (#1608)

* Provides more specific example header

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

* Provides a more specific example header

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

_opensearch/supported-field-types/text.md

@@ -77,7 +77,7 @@ Parameter | Stored values
 Storing positions is useful for proximity queries. Storing character offsets is useful for highlighting.
 {: .tip }
 
-## Example
+### Term vector parameter example
 
 Create a mapping with a text field that stores character offsets in a term vector:
 
@@ -158,4 +158,4 @@ The words "date of birth" are highlighted in the response:
     ]
   }
 }
-```
+```