Added react-teams-message webpart
Added react-teams-message webpart

Added react-teams-message webpart, updated read me file for typos.

AJIXuMuK/sp-dev-fx-webparts,AJIXuMuK/sp-dev-fx-webparts,SharePoint/sp-dev-fx-webparts,SharePoint/sp-dev-fx-webparts,AJIXuMuK/sp-dev-fx-webparts