Add A New Slide

## We Need More Slides
Grab another octocat and create a new slide from scratch.
If you need help, check out the Appendix in the training manual.

Start with the Appendix in the training manual, then identify where the repository's existing slides are stored. Create a new slide from scratch featuring another octocat; done means the added slide is present and matches the project's slide format.

索引モデルが issue の本文から書いたものです。