update readme with new extension names
update readme with new extension names

MitjaBezensek/shouldly,JoeMighty/shouldly,MitjaBezensek/shouldly,ofirw/shouldly,MitjaBezensek/shouldly,MitjaBezensek/shouldly,MitjaBezensek/shouldly,chaitanyagurrapu/shouldly,ankurMalhotra/shouldly,JakeGinnivan/shouldly,AmadeusW/shouldly,MitjaBezensek/shouldly,enkafan/shouldly,KennyBu/shouldly,yannisgu/shouldly