A transcript of a video is slightly different from captions. According The Ohio State University James Kerr blogpost "The difference between captions and transcripts":

"Captions appear onscreen simultaneously with the audio and video, and follows the same timing. It exists within the video player, and generally speaking, can’t be referenced outside of the video. A transcript is the same word-for-word content as captions, but presented in a separate document, whether it is a text file, word processing document, PDF, or web page." 

Video captions are necessary for videos included on your guides. Aim also to create and include a transcript for each library-created video.