docs: improve ES provisioning examples

closes #12281

docs/sources/administration/provisioning.md

@@ -158,7 +158,7 @@ Since not all datasources have the same configuration settings we only have the
 | timeInterval | string | Prometheus, Elasticsearch, InfluxDB, MySQL, PostgreSQL & MSSQL | Lowest interval/step value that should be used for this data source |
 | esVersion | number | Elasticsearch | Elasticsearch version as a number (2/5/56) |
 | timeField | string | Elasticsearch | Which field that should be used as timestamp |
-| interval | string | Elasticsearch | Index date time format |
+| interval | string | Elasticsearch | Index date time format. nil(No Pattern), 'Hourly', 'Daily', 'Weekly', 'Monthly' or 'Yearly' |
 | authType | string | Cloudwatch | Auth provider. keys/credentials/arn |
 | assumeRoleArn | string | Cloudwatch | ARN of Assume Role |
 | defaultRegion | string | Cloudwatch | AWS region |