Adding redirects should allow for selecting anchors

[chrisatxano]

For scenarios where a link like
http://docs.com/this_feature
becomes
https://docs.com/features#this_feature
we should be able to have redirects point to specific anchors instead of just the base page

[JaniceManwiller]

It would also be nice to be able to redirect from an anchor.

I've had specific cases where when a topic gets too long and unwieldy, what used to be sections/anchors are changed to separate topics. But there is no way to redirect in that situation.