Fixes the link of shell to the ink #module-shell

It's about the [mootools/website/issues/27](https://github.com/mootools/website/issues/27). 

Notice it works for Mardown on the github documentation, but the link is to `#module-shell` as on mootools/website it should point to `#module:-shell`
Merge pull request #22 from alain-andre/patch-1

Fixes the link of shell to the ink #module-shell