Markdown is no longer used, remove it

[LeafHacker]

trafficstars

Also rename MainPage to ConfigPage and get rid of the pages package since there is only one page class.

[leijurv]

We could still have an intro or a thank you page

I guess it'll still be in git history

[LeafHacker]

Well if the plan is to add markdown pages I'll leave this un-merged until we decide either way.