Upon opening the folder, I immediately see an issue. Your extensions are wrong.
See how these end in .txt? Most likely this happens because you have extensions hidden on your machine, therefore when you add an extension, there's an additional extension appended but hidden.
Enable extensions. It should be in Explorer > View > File extensions (for Windows 10).
Upon further inspection, I see another error in your custom_story_settings file: It's missing the closing tag.
It should end with /> at the end.
Your extra_english file seems fine, except the extension, and that it should end in
.lang not
_lang.