[DOCS] fixed count docs, it now requires a top-level query object, same as other apis

Relates to #4074

docs/reference/search/count.asciidoc

@@ -14,7 +14,9 @@ $ curl -XGET 'http://localhost:9200/twitter/tweet/_count?q=user:kimchy'
 
 $ curl -XGET 'http://localhost:9200/twitter/tweet/_count' -d '
 {
-    "term" : { "user" : "kimchy" }
+    "query" : {
+        "term" : { "user" : "kimchy" }
+    }
 }'
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