What is the etiquette on updating someones answer with a little bit of extra info

Question

I recently found the answer to a problem I was having here

Git change '.git' folder name in windows

This answer in particular rather than the accepted answer was what fixed my issue

https://stackoverflow.com/a/795575/6244

however I wanted to add another important piece of info to Micheals answer (about adding the new dir name to your .gitignore file).

I felt this info (maybe wrongly) was important enough to be an answer in itself rather than just a comment to micheals answer. However what I really would have like to have been able to do would be to add a note to michaels answer saying that it worked in Windows, and that you should add the dir name to you .gitignore file.

Would this have been ok?

Answer 1

My opinions:

1. It's rude to edit existing answer adding something of your own.
2. It's not proper to post whole new answer based on existing answer just adding something small (not fundamental)

So the way I would choose is posting comment on the existing answer asking its author to add that piece of code.