writerfilter: few more doxygen comments

Change-Id: I4893e2b3297adadf4e19ab22b298aaef4044b52e

writerfilter/qa/cppunittests/rtftok/testrtftok.cxx

@@ -18,6 +18,13 @@
 
 using namespace ::com::sun::star;
 
+/**
+ * Unit test invoking the Writer RTF import filter.
+ *
+ * This does only minimal testing, checking if the filter crashes and returns
+ * the expected bool value for given inputs. More fine-grained tests can be
+ * found under sw/qa/extras/rtfimport/.
+ */
 class RtfTest
     : public test::FiltersTest
     , public test::BootstrapFixture

writerfilter/source/rtftok/rtfsprm.hxx

@@ -18,6 +18,8 @@ namespace writerfilter {
     namespace rtftok {
 
         typedef std::vector< std::pair<Id, RTFValue::Pointer_t> > RTFSprmsImplBase;
+
+        /// The payload of RTFSprms which is only copied on write.
         class RTFSprmsImpl : public RTFSprmsImplBase
         {
         public: