Code collaboration / commenting tool?

I want to give my code to others to critique but I want them to be able to do so easily, as if they were commenting on a document in microsoft word. Github is a bit too complicated for this, and using comments in the script itself is cumbersome and unwieldy for long thoughts. What is the best way to do this?

This isn’t php specific, but I work mostly in php so php specific tools are fine.

How about a personal blog, with links to the codebase?

I guess I am looking for something a little more specific that might be made for situations like this. I suppose a good tool would be able to approach what ms word does. MS word is unsuitable for coding for a lot of reasons, but I have considered using it as a commenting tool in the past, but I am hoping a better tool exists.

Google Drive?