doxygen docs: Add missing Elementary group

Elementary has a main page (elementary_main) like other libs (Ecore, Evas...)
but it was missing a doxygen group like the other libs. This group is not
terribly useful but it is manually referenced from dozens of places, resulting
in lots of warnings.
I thought this solution is simpler than removing all the manual references.

1 files changed, 6 insertions, 0 deletions

diff --git a/doc/main.dox b/doc/main.dox
index 46f3c4edca..a09e1548ec 100644
--- a/doc/main.dox
+++ b/doc/main.dox
@@ -261,3 +261,9 @@
  *
  * @brief Physics simulation integration and visual effects.
  */
+
+/**
+ * @defgroup Elementary Elementary
+ *
+ * @brief Widget library (See the @ref elementary_main main page).
+ */