Upload an image, video or audio file that can then be attached to a recognition or an achievement. Supported image file types are JPG, GIF, and PNG. Supported video file types include AVI, FLV, and WHV. Supported audio files types include WAV, MP3, and M4A. Maximum image file size is 10 MB, and maximum video/audio file size is 100 MB. The file owner will be either the currently authenticated user (if applicable), or the client application. This endpoint requires an access token with a requested scope of 'write'.