docs: update for 5.0.0-beta.16
docs: update for 5.0.0-beta.16

Americas/sequelize,sequelize/sequelize,jayprakash1/sequelize,jayprakash1/sequelize,yjwong/sequelize,overlookmotel/sequelize,overlookmotel/sequelize,sequelize/sequelize,inDream/sequelize,sequelize/sequelize,inDream/sequelize,Americas/sequelize