Add a section to the GUIDE for "Thread support"
Add a section to the GUIDE for "Thread support"

icebreaker/byebug,icebreaker/byebug,k0kubun/byebug,guilherme/byebug,miamiruby/byebug,deivid-rodriguez/byebug,k0kubun/byebug,os97673/byebug,saisai/byebug,yui-knk/byebug,scalp42/byebug,deivid-rodriguez/byebug,guilherme/byebug,ozydingo/byebug,scalp42/byebug,yui-knk/byebug,deivid-rodriguez/byebug,os97673/byebug,saisai/byebug,webdev1001/byebug,yui-knk/byebug,webdev1001/byebug,miamiruby/byebug,guilherme/byebug,k0kubun/byebug,ozydingo/byebug