update documentation to say default is false

ingest-app/docs/api.md

@@ -159,8 +159,10 @@ The following fields are validated:
 * [Data Format](https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/dataformat?format=csv) - Archival and Distribution File Format, and GetData Format
 * [ProcessingLevel] (https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/productlevelid?format=csv) - productlevelid
 
-**Note**: cmr-validate-keywords is set to TRUE by default
+**Note**: if cmr-validate-keywords header is not set explicitly, it will behave as if it was set to FALSE by default behind the scenes
+
 **Note**: that when multiple fields are present the combination of keywords are validated to match a known combination.
+
 **Note**: Among the validation fields above, [Platforms], [Instruments], [Projects], [Science Keywords], [Location Keywords] and [Data Centers] are also validated when the `Cmr-Validate-Keywords` header is not set to `true` except that  validation errors will be returned to users as warnings.
 
 **Note**: the following fields are always checked: