[DOCS] Removed the experimental label from Tribe, Hot Threads

and Completion Suggester

docs/reference/cluster/nodes-hot-threads.asciidoc

@@ -3,14 +3,14 @@
 
 An API allowing to get the current hot threads on each node in the
 cluster. Endpoints are `/_nodes/hot_threads`, and
-`/_nodes/{nodesIds}/hot_threads`. This API is experimental.
+`/_nodes/{nodesIds}/hot_threads`.
 
 The output is plain text with a breakdown of each node's top hot
-threads. Parameters allowed are: 
+threads. Parameters allowed are:
 
 [horizontal]
-`threads`:: 	number of hot threads to provide, defaults to 3. 
+`threads`:: 	number of hot threads to provide, defaults to 3.
 `interval`:: 	the interval to do the second sampling of threads.
-				Defaults to 500ms. 
+				Defaults to 500ms.
 `type`:: 		The type to sample, defaults to cpu, but supports wait and
 				block to see hot threads that are in wait or block state.

docs/reference/modules/tribe.asciidoc

@@ -4,8 +4,6 @@
 The _tribes_ feature allows a _tribe node_ to act as a federated client across
 multiple clusters.
 
-WARNING: This feature is EXPERIMENTAL -- use at your own risk.
-
 The tribe node works by retrieving the cluster state from all connected
 clusters and merging them into a global cluster state. With this information
 at hand, it is able to perform read and write operations against the nodes in

docs/reference/search/suggesters/completion-suggest.asciidoc

@@ -8,11 +8,6 @@ The `completion` suggester is a so-called prefix suggester. It does not
 do spell correction like the `term` or `phrase` suggesters but allows
 basic `auto-complete` functionality.
 
-IMPORTANT: This feature is marked as experimental. This means, that
-the API is not considered stable, and that you might need to reindex
-your data after an upgrade in order to get suggestions up and running
-again. Please keep this in mind.
-
 ==== Why another suggester? Why not prefix queries?
 
 The first question which comes to mind when reading about a prefix