Update CONTRIBUTING.md
Update CONTRIBUTING.md

Add a note about using GitHub issues for architecture astronaut-ism and other enjoyable (Redux-relevant!) topics.

To quote @dan_abramov (https://twitter.com/dan_abramov/status/702664100137070592)

> We encourage discussions in issues. Just not “my codez don’t work” kind of questions.
jas-chen/typed-redux,doerme/redux,jas-chen/typed-redux,gaearon/redux,joaomilho/redux,CompuIves/redux,jas-chen/redux,tatsuhino/reactPractice,mjw56/redux,ptkach/redux,bvasko/redux,tappleby/redux,roth1002/redux,neighborhood999/redux,mjw56/redux,Aweary/redux,CompuIves/redux,neighborhood999/redux,splendido/redux,doerme/redux,leoasis/redux,tatsuhino/reactPractice,joshwreford/idle-game,gaearon/redux,chentsulin/redux,tappleby/redux,splendido/redux,roth1002/redux,jas-chen/redux,lifeiscontent/redux,tappleby/redux,javascriptjedi/redux-select,joshwreford/idle-game,ptkach/redux,bvasko/redux,Aweary/redux,lifeiscontent/redux,chentsulin/redux,joaomilho/redux