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.

Locate the repository's existing slide structure and compare a few current slides before starting. Read the Appendix in the training manual for guidance, then create one additional slide from scratch using another octocat; done means the new slide is present and consistent with the project's existing presentation.

索引モデルが issue の本文から書いたものです。