all those files that had to be changed were updated or new ones were added to the framework, then I couldn't get it done. Would you please show me how to apply it in a recent framework version
Are you referring to the grunt files that handle the dev/build tasks? If so, sorry but I actually don't know how to do it in the latest version - as we don't use that here.
You can either have a run through the files to figure it out for yourself or you can switch to the build tool we use - RUB - the develop version of which can be configured to look for .txt files instead of .json