rule: last line should end with a line break

[naturallymitchell]

https://stackoverflow.com/questions/729692/why-should-text-files-end-with-a-newline

that explains it well. my thought was, a new line begins at the end of the previous line

benefits: diffs, readability, ..

https://en.wikipedia.org/wiki/Newline
https://www.reddit.com/r/algorithms/search?q=diff&restrict_sr=on