Added CONTRIBUTING.md file
Added CONTRIBUTING.md file

davask/exim-cms,Soullivaneuh/sonata-sandbox,davask/exim-cms,KonstantinBY/sonata-sandbox,davask/exim-cms,davask/exim-cms,sonata-project/sandbox,tworzenieweb/polcode-recruitment,tworzenieweb/polcode-recruitment,KonstantinBY/sonata-sandbox,sonata-project/sandbox,sonata-project/sandbox,rzproject/sandbox,zsamotsil/polcode_task,Soullivaneuh/sonata-sandbox,rzproject/sandbox,Soullivaneuh/sonata-sandbox,Soullivaneuh/sonata-sandbox,zsamotsil/polcode_task,KonstantinBY/sonata-sandbox,KonstantinBY/sonata-sandbox,rzproject/sandbox