Add reading order to a 17th Shard subdomain

[cmpickle]

currently this uses the default github pages domain of https://17thshard.github.io/reading-order but it would be nice to make it a subdomain like has been done for shardle and the map of roshar. Something like reading-order.17thshard.com

[jofwu]

So, this was an intentional decision for a few reasons.

1. Part of it is that we (or I at least) didn't feel like it had the right level of polish to be hosted in the 17S domain. It feels a bit too unfinished and unrefined to me.

2. The other large part is that reading orders can be contentious. Lots of people have different strong opinions about the "best" reading order. As for as the reading order recommended by this tool, it's really just my personal take on a reading order. I was uncomfortable with the idea of hosting it on the 17S domain, where it would perhaps imply that it is "the official 17th Shard recommended reading order".

Obviously the first of these issues we can get around with a bit more work, perhaps. I'd have to consider what would be needed to waive the second issue... Off the top of my head... It's possible I could get staff to buy off on it, maybe along with some verbiage somewhere to soften the idea that it's "official". Another idea would be to rework it in some way that allows for a few different reading order versions. So instead of one reading order option you go to a "Reading Order View" and then get a drop down menu with a few different choices? Each with a description? Big bonus points if you let users create their own in some way??? But that's getting off topic of this particular issue. :)

The point is, if we want to make this move I think it needs a bit more work and refinement. I'll have to sit down and work out some specific goals that I would want to see met first, perhaps.