Doc: use standard wording in \brief commands

QDoc does some magic with the \class and \namespaces
and \brief commands, so the following wording must be used:
"The xxx class yyy ..."

Change-Id: Id231f30e8464898b776888d5423523de404aae34
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/libs/qmljs/qmljscontext.cpp

@@ -36,7 +36,8 @@ using namespace QmlJS::AST;
 
 /*!
     \class QmlJS::Context
-    \brief Holds information about relationships between documents in a Snapshot.
+    \brief The Context class holds information about relationships between
+    documents in a Snapshot.
     \sa Document Link Snapshot
 
     Contexts are usually created through Link. Once created, a Context is immutable