Make email address for bridges consistent
[BridgeDB](https://bridges.torproject.org) claims that users should email bridges[at]torproject.org but [our website](https://2019.www.torproject.org/docs/bridges) mentions bridges[at]bridges.torproject.org. This confused at least one user over at legacy/trac#18076 and, frankly, me too.
I created a patch in the following GitHub branch:
https://github.com/NullHypothesis/webml/tree/update-bridge-docs
It makes our documentation consistent by changing the email address to bridges[at]torproject.org.
issue