Deleted discontinued chapters (#598)

The links don't exist anymore

README.md

@@ -23,19 +23,15 @@ Here are our official chapters. Let us know if you are interested in [starting o
 * [Bhubaneswar](https://www.facebook.com/groups/pwlbbsr/)
 * [Boston](http://www.meetup.com/Papers-We-Love-Boston-Cambridge/)
 * [Brasilia](http://www.meetup.com/papers-we-love-bsb)
-* [Boulder](http://www.meetup.com/Papers-We-Love-Boulder/)
 * [Bucharest](http://www.meetup.com/papers-we-love-bucharest/)
 * [Buenos Aires](https://paperswelove.org/buenos-aires/)
 * [Cairo](http://www.meetup.com/Papers-We-Love-Cairo/)
 * [Chattanooga](http://www.meetup.com/Papers-We-Love-Chattanooga/)
 * [Chicago](http://www.meetup.com/papers-we-love-chicago/)
 * [Columbus, Ohio](http://www.meetup.com/Papers-We-Love-Columbus/)
-* [Dallas](http://www.papersdallas.com/)
 * [Gothenburg](https://www.meetup.com/Papers-We-Love-Gothenburg/)
-* [Guadalajara](https://www.facebook.com/pwlgdl/)
 * [Hamburg](http://www.meetup.com/Papers-We-Love-Hamburg/)
 * [Hyderabad](http://www.meetup.com/papers-we-love-hyderabad/)
-* [Iasi](http://www.meetup.com/Papers-We-Love-Iasi/)
 * [Iowa City](https://www.meetup.com/techcorridorio)
 * [Kathmandu](https://www.facebook.com/groups/PapersWeLoveKathmandu/)
 * [Kyiv](https://www.facebook.com/groups/PapersWeLoveKyiv)
@@ -43,18 +39,11 @@ Here are our official chapters. Let us know if you are interested in [starting o
 * [London](http://www.meetup.com/papers-we-love-london)
 * [Los Angeles](http://www.meetup.com/papers-we-love-la)
 * [Madrid](http://www.meetup.com/Papers-We-Love-Madrid/)
-* [Medellín](https://www.meetup.com/paperswelovemde/)
 * [Montreal](http://www.meetup.com/Papers-We-Love-Montreal/)
-* [Mumbai](https://www.meetup.com/Papers-We-Love-Mumbai/)
-* [Munich](http://www.meetup.com/Papers-We-Love-Munich/)
 * [New York City](http://www.meetup.com/papers-we-love/)
 * [Paris](http://www.meetup.com/Papers-We-Love-Paris/)
-* [Philadelphia](http://www.meetup.com/Papers-We-Love-Philadelphia/)
-* [Portland](http://www.meetup.com/Papers-We-Love-PDX/)
-* [Porto](https://www.meetup.com/Papers-We-Love-Porto)
 * [Pune](http://www.meetup.com/Doo-Things)
 * [Raleigh-Durham](https://www.meetup.com/Papers-We-Love-Raleigh-Durham/)
-* [Reykjavík](http://www.meetup.com/Papers-We-Love-Reykjavik)
 * [Rio de Janeiro](https://www.meetup.com/pt-BR/papers-we-love-rio-de-janeiro/)
 * [San Diego](http://www.meetup.com/Papers-We-Love-San-Diego/)
 * [San Francisco](http://www.meetup.com/papers-we-love-too/)