Add knex query lab link to readme.
Add knex query lab link to readme.

joeframbach/knex,galenandrew/knex,CorvusCorrax/knex,harriha/knex,whitelynx/knex,maxcnunes/knex,tgriesser/knex,abegines/knex,statyan/knex,WaltRock/knex,wubzz/knex,maxcnunes/knex,vellotis/knex,chuym/knex,tgriesser/knex,wubzz/knex,tgriesser/knex,chuym/knex,WaltRock/knex,carragom/knex,whitelynx/knex,joeframbach/knex,Atlantis-Software/knex,chuym/knex,noodle/knex,vellotis/knex,whitelynx/knex,galenandrew/knex,vellotis/knex,statyan/knex,carragom/knex,Atlantis-Software/knex,maxcnunes/knex,joeframbach/knex,abegines/knex,CorvusCorrax/knex,harriha/knex,harriha/knex,noodle/knex,galenandrew/knex