Update scenarios-mqtt.md
Update scenarios-mqtt.md

Fixed typos

khorne3/docs,sandrinodimattia/docs,Annyv2/docs,yvonnewilson/docs,Catografix/docs,jeffreylees/docs,yvonnewilson/docs,khorne3/docs,jeffreylees/docs,yvonnewilson/docs,jeffreylees/docs,Catografix/docs,Annyv2/docs,hamzawi06/docs,Annyv2/docs,sandrinodimattia/docs,auth0/docs,auth0/docs,sandrinodimattia/docs,miparnisari/docs,hamzawi06/docs,hamzawi06/docs,Catografix/docs,auth0/docs,khorne3/docs