if first element is not the top-most element in a document navigation, it would break since it would only look at the first element's depth, instead of taking the highest ranking element's depth.
removes the top-level rendering of "Examples" in the document navigation for functions, since functions have examples in each overload instead of at the generic symbol level.
adds support for individual example titles being rendered in the document navigation, unlike before where it would only render "Examples" without any sub-elements.
Fixes https://github.com/denoland/deno-docs/issues/573.
Fixes 3 things: