adding missing example config file

Author: jholloc

examples/simple_mapper/config.toml.in

@@ -0,0 +1,14 @@
+mapping_directory = "@CMAKE_CURRENT_SOURCE_DIR@/mappings"
+schemas_directory = "@CMAKE_SOURCE_DIR@/schemas"
+trace_enabled = true
+cache_enabled = true
+custom_function_libraries = [
+    "@CMAKE_CURRENT_BINARY_DIR@/libcustom_library@CMAKE_SHARED_LIBRARY_SUFFIX@"
+]
+
+[data_source_factories]
+json_factory = "@CMAKE_CURRENT_BINARY_DIR@/libjson_data_source@CMAKE_SHARED_LIBRARY_SUFFIX@"
+
+[data_sources.JSON]
+factory = "json_factory"
+args.data_root = "@CMAKE_CURRENT_SOURCE_DIR@/data"