Consider making package sidebar sticky when scrolling down package readme

[parlough]

As you scroll down a long readme of a package, the right sidebar stays aligned with the content. However, it could scroll with the page, as the space it occupies is unused, providing quicker access to the contents.

Alternatively, a return to top button could appear on scrolling up if it's preferred to keep the page focused.

[sigurdm]

What if the sidebar doesn't fit in one screen height?

[sigurdm]

Maybe there is a css-option so that it scrolls down until the end, and then sticks.

position: sticky

maybe...