Update site.rst

The community has been renamed from Oldenburg (ffol) to Nordwest (ffnw) to include other cities. Also the git url has changed.
Merge pull request #1 from freifunk-gluon/master

gluon changes
Merge pull request #2 from freifunk-gluon/master

gluon changes
Merge pull request #201 from bioxz/master

Community name change from Freifunk Oldenburg to Freifunk Nordwest