Ignore lyrics graphs.

Signed-off-by: Varun Ravishankar <vrdabomb@gmail.com>
Add empty file so data/graphs exists.

Signed-off-by: Varun Ravishankar <vrdabomb@gmail.com>
Write lyrics graphs to data/graphs.

Signed-off-by: Varun Ravishankar <vrdabomb@gmail.com>