add links to issue-tracker & open-data on NYC 311 web homepage

[davidmooreppf]

From page ::

http://www1.nyc.gov/311/index.page

... unless I'm missing it, I don't see a link to "report issue" or "suggest feature"

Link towards bottom of page (or footer) should link to correct maintained public repo.

And unless I'm missing it, I don't see a big friendly link to "get 311 data".

Link twds bottom, again, to that beast of an NYC open data portal.

cc @noneck - feel free to let me know if this is not the correct location and I'll reassign, didn't seen an "official 311" repo.