update caption, try to change to a different theme to see if that fixes wcag issues

Author: Susan Vanderplas

_quarto.yml

@@ -111,8 +111,8 @@ format:
     css: ['build_deps/style.css']
     highlight-style: a11y
     theme:
-      light: ['cosmo', build_deps/callouts.scss]
-      dark: ['cyborg', build_deps/callouts.scss]
+      light: ['flatly', build_deps/callouts.scss]
+      dark: ['darkly', build_deps/callouts.scss]
     code-link: true
     include-in-header: "build_deps/header.html"
     code-copy: true

index.qmd

@@ -24,7 +24,7 @@ I've made an effort to use some specific formatting and enable certain features
 
 The book contains a number of features which should help you navigate, use, improve, and respond to the textbook.
 
-![Textbook features, menus, and interactive options](images/how-to-use/Textbook-features.png){fig-alt="There are a number of interactive features available in this textbook. There is a search bar on the left sidebar, along with links to each chapter. On the right, there is a menu specific to the sections in each chapter - this helps you navigate within the chapter. There is also a link to \"Edit this page\" that allows you to submit a correction to the textbook via Github. At the bottom, there is a link to the next chapter, but there are also reaction emoji that allow you to express yourself after you read the chapter. If you log in via GitHub, you can also leave comments, start discussions, or ask questions using the github discussion integration at the bottom of the page."}
+![Textbook features, menus, and interactive options](images/how-to-use/Textbook-features.png){fig-alt="There are a number of interactive features available in this textbook. There is a search bar on the left sidebar, along with links to each chapter. On the right, there is a menu specific to the sections in each chapter - this helps you navigate within the chapter. There is also a link to \"Edit this page\" that allows you to submit a correction to the textbook via Github. If you log in via GitHub, you can also leave comments, start discussions, or ask questions using the github discussion integration at the bottom of the page. At the bottom, there is a link to the next chapter, but there are also reaction emoji that allow you to express yourself after you read the chapter."}
 
 ### Special Sections {.unnumbered}