Update community plugins documentation

Added a note for non supportability of community plugins.

docs/user/plugins.asciidoc

@@ -18,7 +18,8 @@ Plugin developers must release a new version of their plugin for each new {kib}
 == Known plugins
 
 The known plugins were tested for {kib} *5.x*, so we are unable to guarantee compatibility with your version of {kib}. The {kib} installer rejects any plugins that haven't been published for your specific version of {kib}. 
-We are unable to evaluate or maintain the known plugins, so care should be taken before installation.
+
+[Important] Known plugins are developed outside of the Elastic company, hence we are unable to evaluate or maintain these plugins. In case of facing any issue with community plugins, it is unsuported by Elastic. Customers should create an issue directly to the repository owner.
 
 [float]
 === Apps
@@ -182,4 +183,4 @@ you must specify the path to that configuration file each time you use the `bin/
 0:: Success
 64:: Unknown command or incorrect option parameter
 74:: I/O error
-70:: Other error
+70:: Other error