Make it more clear that discriminator is not for validation

Co-authored-by: Darrel <[email protected]>

Author: jdesrosiers

versions/3.1.1.md

@@ -2727,7 +2727,7 @@ MyResponseType:
   - $ref: '#/components/schemas/Lizard'
 ```
 
-which means the payload _MUST_, by validation, match exactly one of the schemas described by `Cat`, `Dog`, or `Lizard`. Evaluating a `oneOf` can be a costly operation, so `discriminator` MAY be used as a "hint" to improve the efficiency of validation and selection of the matching schema. The `discriminator` keyword can not change the validation result of the `oneOf`, it can only help make the evaluation more efficient and provide better error messaging. We can then describe exactly which field tells us which schema is expected to match the instance:
+which means the payload _MUST_, by validation, match exactly one of the schemas described by `Cat`, `Dog`, or `Lizard`. Evaluating a `oneOf` can be a costly operation, so `discriminator` MAY be used as a "hint" to improve the efficiency of selection of the matching schema. The `discriminator` keyword can not change the validation result of the `oneOf`, it can only help make the evaluation more efficient and provide better error messaging. We can then describe exactly which field tells us which schema is expected to match the instance:
 
 ```yaml
 MyResponseType: