Add UI for the floor option or document in README

[edmorley]

I only happened to realise there was an option to show the top X objects (eg /_dozer/index?floor=1000) after seeing the equivalent feature in https://github.com/munhitsu/django-dowser

It would be great if there was UI for this, or alternatively a mention in the README :-)

[mgedmin]

That's a very sensible request. I would be happy to merge a PR, if you'd care to produce one. UI would be more discoverable than a README, I think.

(Some background: I took over Dozer's maintainership when the original maintainer lost interest. I've only used the profiler/log viewer parts of it. I had no idea this feature existed either.)