Update console.asciidoc

Per a slack discussion https://elastic.slack.com/archives/C0D1XEXEZ/p1628706191394900

There is a misleading issue with Kibana > Dev Tools, regarding posting a GET request with a body, in particular say a search.  

GET [index]/_search {....} this gets converted to a POST request.  It can be seen if you are looking at the console view in the browser tools.

This can cause different responses (different results) when using Kibana versus other tools ex. POSTMAN when diagnosing something such as a search query with aggs.

See references: 
#11593
#11125
#11948

This doc change is to add it so that is it more obvious that we do this (transform to POST when GET has body).

docs/dev-tools/console/console.asciidoc

@@ -49,6 +49,8 @@ click the action icon (image:dev-tools/console/images/wrench.png[]) and select *
 Once copied, the username and password will need to be provided
 for the calls to work from external environments.
 
+Note: If you post a GET request with a body, will be automaically be converted to *Console* syntax as a POST request.
+
 [float]
 [[console-autocomplete]]
 ==== Autocomplete