Improve documentation wording

Author: obrok

lib/concurrent/actor/behaviour/buffer.rb

@@ -4,9 +4,9 @@ module Behaviour
 
       # Any message reaching this behaviour is buffered. Only one message is is scheduled
       # at any given time. Others are kept in buffer until another one can be scheduled.
-      # This effective means that messages handled by behaviours before buffer have higher priority
-      # and they can be processed before messages arriving into buffer. This allows to
-      # process internal actor messages like (`:link`, `:supervise`) processed first.
+      # This effectively means that messages handled by behaviours before buffer have higher priority
+      # and they can be processed before messages arriving into buffer. This allows for
+      # the processing of internal actor messages like (`:link`, `:supervise`) first.
       class Buffer < Abstract
         def initialize(core, subsequent)
           super core, subsequent