Add a section about using / or /root as docroot

```/root``` and ```/``` are not good places to run your website from, even if in subfolders inside there.  Both directories are root-only locations where you wouldn't want to give a webserver write access at all, since it can cause some risks to the system.
Rewrite to 80char limits per line
Merge pull request #8 from teward/patch-1

Add a section about using `/` or `/root` as docroot