Edit bioacoustics/BUOW spectrogram video and add bat examples

[valerieporter]

List of things to fix in bioacoustics video:

• add bat spectrograms to video
• make a supertitle like "Auto Species ID for Soundscape Audio Recordings"
• make more clear spectrogram titles (bigger font size too)
• increase the font size of the axes' titles and change to: y-axis: Frequency (Hz) [or (kHz) for bats]
• make overlaid species labels more clear (add a species label table below? like in Raven?)
• make all background black (needs review from Ian)