Clarification on insert_final_newline behavior for empty files about specification

[cxw42]

I think this is a duplicate of of editorconfig/editorconfig#416

[randstr]

Empty files have zero lines, so there's nothing to terminate. Adding a newline in that case would inserting a new (empty) line, which is just wrong. Editors and linters that don't respect this behavior are buggy.

For the specification, yes, it can be clarified if necessary, to help implementers avoid mistakes. Is that necessary?

[cxw42]

Per @ppalaga at editorconfig/editorconfig#416 (comment) , I agree with clarifying the specification to state expressly that editors shall not insert newlines in empty files when saving those files with insert_final_newline = true.