Add mod documentation in seven languages

locale/en.properties

@@ -1,2 +1,2 @@
 mod_schema_base_name = Schemas
-mod_schema_base_desc = Annotations as data: schemas/*.json files of any mod describe scenario actions and commands (parameters, types, entity references) and the fields of entity kinds — their own and other mods'. The catalog merges them in load order, the checker validates values, the line writer builds scenario lines, the index knows the ids of any kind. The validator, the data editors and the Data Editor window build on it.
+mod_schema_base_desc = Lets every mod describe its scenario actions, DSL commands and data fields as data; the tools build forms, pickers and checks from these descriptions.