Fixed missing images in NCK / Building + Mounting

Most if not all of the images in the construction kit [Building + Mounting](http://communitytechnology.github.io/docs/cck/index.html#building-mounting) were missing, this pull request adds them in. Also fixed a little bit of text, image tags, etc.

@sifrwahid - Take a look, I tested in a local instance and it appears that everything is fixed.