The Stanford Canvas Team converted an open-source command line app into a web app which allows instructors to create quiz questions in Microsoft Word or a text editor and import such questions into Canvas Quizzes.
Follow the formatting instructions when writing up your quiz. Once the plain text (*.txt) file is ready to be converted, refer to the instructions to convert your text file to QTI file and upload the conversion to Canvas.
Note: access to the Text to QTI web app requires an active SUNet ID.