They've always asked that others not host development documentation. Lots of us keep a local copy either for playing around or helping improve them, but you've clearly posted this as a preview of Bootstrap 3 without any permission from Mark.
It's open-source, man.
I did not changed any copyrights or licenses.
Btw, I was impressed with what I saw today morning and just wanted to share my impression with other guys.
Btw, I've asked @mdo's opinion. Waiting for the answer.