Included autogenerated code to the ign_create_docs function (#76) (#79)

Signed-off-by: ahcorde <[email protected]>

CMakeLists.txt

@@ -85,6 +85,13 @@ configure_file(${CMAKE_SOURCE_DIR}/tutorials.md.in ${CMAKE_BINARY_DIR}/tutorials
 ign_create_docs(
   API_MAINPAGE_MD "${CMAKE_BINARY_DIR}/api.md"
   TUTORIALS_MAINPAGE_MD "${CMAKE_BINARY_DIR}/tutorials.md"
+  AUTOGENERATED_DOC "${CMAKE_BINARY_DIR}/include/ignition/msgs/"
   TAGFILES
     "${IGNITION-MATH_DOXYGEN_TAGFILE} = ${IGNITION-MATH_API_URL}"
 )
+
+# Wait to build the doc for the autogenerated code
+# The TARGET will exist if doxygen is installed
+if(TARGET doc)
+  add_dependencies(doc ignition-msgs${PROJECT_VERSION_MAJOR})
+endif()