readme: update bridge URL [ci skip]
Points at the Bridge repo's README rather than its releases page.
@@ -10,7 +10,7 @@ A personal server operating function.
[azim]: https://etherscan.io/address/0x223c067f8cf28ae173ee5cafea60ca44c335fecb
[aens]: https://etherscan.io/address/azimuth.eth
-[brid]: https://github.com/urbit/bridge/releases
+[brid]: https://github.com/urbit/bridge
[arvo]: https://github.com/urbit/urbit/tree/master/pkg/arvo
## Install
