Adds StackExhange to footer.php
Adds StackExhange to footer.php

I think that the current StackExchange site is mature enough to be included in the footer since it's already in the `/support` page.
luiscauro/mvp,jgabriellima/mvp,ethan42411/mvp,Sesshoumaru404/mvp,sineld/mvp,btkostner/mvp,Sesshoumaru404/mvp,arunlodhi/mvp,ericramirez/mvp,Sesshoumaru404/mvp,elementary/website,LinkBR/mvp,learnercys/mvp,btkostner/mvp,ericramirez/mvp,ethan42411/mvp,elementary/mvp,arunlodhi/mvp,LinkBR/mvp,elementary/mvp,elementary/website,charanrajtc/mvp,jpcarvalho1992/mvp,ericramirez/mvp,luiscauro/mvp,jpcarvalho1992/mvp,sineld/mvp,jpcarvalho1992/mvp,LinkBR/mvp,hyptos/mvp,elementary/website,ethan42411/mvp,jgabriellima/mvp,learnercys/mvp,learnercys/mvp,hyptos/mvp,charanrajtc/mvp,sineld/mvp,luiscauro/mvp,btkostner/mvp,jgabriellima/mvp,hyptos/mvp,charanrajtc/mvp,arunlodhi/mvp,elementary/mvp