How to query elasticsearch datasource in grafana?

@darion 

To query an Elasticsearch datasource in Grafana, follow these steps:

1. Log in to Grafana and go to your dashboard. Click on "Add Panel" and select the "Query" option.
2. In the Data Source dropdown menu, select Elasticsearch.
3. Click on the "Select Measurement" dropdown menu and choose the Elasticsearch index you want to query.
4. Specify the fields you want to query and set any other filters or aggregations as needed.
5. Click on the "Run Query" button to see the results of your query.
6. You can further customize your query by using Elasticsearch Query DSL or ElasticSearch SQL.
7. Once you are satisfied with the query results, you can save your panel or dashboard for future reference.