Update live markets site to serve the contents of this repository

[cbeams]

The dan-da/bitsquare_markets repository was moved here to bisq-network/markets with bisq-network/dao#30, but the live https://markets.bisq.network site is still serving the contents of the old repository.

If @dan-da chooses to fill the role of Markets Website+API Operator/Maintainer (bisq-network/roles#9), then we can continue using his existing hosting infrastructure, and do little more than update the Git remote that the live site is being served from. If not, we'll want to stand up the markets app on new hosting infrastructure under (probably @cbeams's Heroku account) until we transition this role to a new owner.