Add a question and change the type of question to "File Upload"
You will get this warning:
Once you confirm that you will be sending to people you know and then you will be allowed to set the size of the file (up to 10000 MB) and the type.
You can leave this on all types of you can limit the type to images, PDF, Video, Audio, etc. This would require an acceptable extension to allow the upload.
Happy Friday!