Option to download Teaser (Glow-worm)

[XXXBold]

Hi, first let me thank you for this great project!

It would be nice to have the option to download the teaser for "Ward" aswell.
If you're interested, it could be implemented like this, using worm-scraper with other parameters:

• Just download it as a standalone book, like the other two (Option example: --book=glow-worm-teaser)
• Add it as chapter to "Ward" at the beginning (Option examples: --book=ward-include-teaser or --book=ward --include-teaser)

Let me know what you think about it :)

[nightpool]

IMO the glow-worm chapters should be included at the beginning of Ward in any format the story is distributed in, I'd be happy to work on a PR for this if there's interest