Issue reported to godot-cpp 1987

Missing quotes only processes the first doc source xml file.

Author: enetheru

CMakeLists.txt

@@ -59,7 +59,7 @@ file(GLOB_RECURSE DOC_XML LIST_DIRECTORIES NO CONFIGURE_DEPENDS "${PROJECT_SOURC
 # conditionally add doc data to compile output
 if(DOC_XML)
     if(GODOTCPP_TARGET MATCHES "editor|template_debug")
-        target_doc_sources(${LIBNAME} ${DOC_XML})
+        target_doc_sources(${LIBNAME} "${DOC_XML}")
     endif()
 endif()