MDL-16389 meta course help file update

lang/en_utf8/help/metacourse.html

@@ -1,7 +1,5 @@
-<h1>Meta Course</h1>
+<h1>Meta course</h1>
 
-<p>Activating this option means this course may be used  as a common area to allow Participants in specific courses to interact with each other.</p>
+<p>A meta course takes enrolments (and other role assignments) from a "child" course or courses. In other words, for every child course added to the meta course, all students (and users in other roles) are also enrolled in the meta course.</p>
 
-<p>A Meta Course can be used to group related courses - for example related subject areas or courses that make up a particular qualification.</p>
-
-<p>Participants may be added via the Student area within the Administration block in the Meta Course.</p>
+<p>Individual students cannot be added to a meta course, only child courses via the "Child courses" link in the course administration bock.</p>