If we update to Jupyter Book 2 (PR #196), the header at the top becomes more cluttered and takes up more vertical space, pushing the page content down. It's very minor, but I liked the old visual style better. Do we care? See below:

For instance:

• this PR adds four icons for the copyright license, which doesn't seem needed on every page, and there is already a copyright notice in the page footer
• this PR adds some icon (it looks like a hamburger bun without the hamburger?) that isn't clickable and isn't active and doesn't do anything, which we presumably don't need.
• this PR adds a button to go to the specific file in Github for this section, which doesn't seem needed, given that we already have a link to the Github repository
• this PR adds a big search bar that is expanded all the time, whereas the old format used a small icon and the search bar expands only when one clicks on it; I liked the old way better
• with this PR, there are now two rows of stuff at the top, whereas the old style had only a single row of stuff
• with this PR, the icon for dark mode is bigger than the other icons