Update cities.md

Clean up some stale / dead events, fix some URLs

Author: btsea

cities.md

@@ -23,33 +23,32 @@ As a disclaimer, BitDevs NYC has no official associations with or oversight of t
 - [Buenos Aires](https://www.bitdevsba.org/)
 - [Chicago](https://chibitdevs.org/)
 - [Curitiba](https://curitibabitdevs.org/)
-- [Denver](http://denverbitdevs.com/)
+- [Denver](https://x.com/denverbitdevs)
 - [Florianópolis](https://floripabitdevs.org/)
 - [Guadalajara](https://bitdevs.btcgdl.com/)
 - [Honolulu](http://www.honolulubitdevs.com/)
 - [London](https://londonbitdevs.org/)
 - [Los Angeles](https://bitdevsla.org/)
 - [Louisville](https://loubitdevs.org/)
+- [Melbourne](https://melb.bitdevs.com.au/)
 - [Mexico City](https://cdmxbitdevs.org)
 - [Miami](https://miamibitdevs.org/)
 - [Minneapolis](https://bitdevsmpls.org)
 - [Nashville](https://nashbitdevs.org)
-- [Norfolk](https://norfolkbitdevs.org/)
-- [Oslo](https://www.meetup.com/bitcoin-developers-oslo/)
 - [Paris](https://twitter.com/bitdevsfr)
-- [Perth](https://perth.bitdevs.com.au/)
+- [Perth](https://github.com/PerthBitDevs/PerthBitDevs)
 - [Portland](https://www.meetup.com/portlandbitdevs/)
 - [Porto Alegre](https://poabitdevs.org/)
 - [Raleigh / Durham / Chapel Hill](https://trianglebitdevs.org/)
-- [San Francisco](https://www.sfbitcoindevs.org/)
+- [San Francisco](https://sfbitcoindevs.org/)
 - [San Juan](https://sanjuanbitdevs.org/)
 - [San Salvador](https://bitdevelsalvador.com/)
 - [São Paulo](https://bitdevsportugues.org)
 - [Seattle](https://github.com/reardencode/seattle_bitdevs)
 - [Singapore](https://bitdevs.sg/)
-- [Sydney](https://bitcoinsydney.org)
+- [Sydney](https://www.meetup.com/bitcoin_sydney/)
 - [Taipei](https://bitdevs.tw/)
 - [Tampa](https://tampabitdevs.io/)
 - [Vancouver](https://bitdevs.ca/)
 - [Victoria](https://bitdevsvictoria.org/)
-- [Washington, D.C.](https://dcbitdevs.org/)
+- [Washington, D.C.](https://dcbitdevs.com/)