Restyle the Slides

## Do you have an eye for design?
Help us improve the look of the slide deck.
If you need help, check out the Appendix in the training manual.

Start by locating the slide deck and reading the Appendix in the training manual for the stated design context. Define the visual changes needed before making edits, and consider the work done when the deck has a consistent, improved presentation.

索引モデルが issue の本文から書いたものです。