API menu always loads with "Properties" open

[krzysdz]

Steps to reproduce

1. Open API menu
2. Open Methods submenu from any object (e.g. Response)
3. Select any method from the list
4. (if on mobile) open the menu

What happens

The menu on the loaded page shows the properties submenu of the selected object, even if something from "Methods" or "Events" was chosen.

What should happen

Ideally, the menu would either have the last selected submenu open, or the submenu would reflect the current section in the documentation (based on scroll position).

Other solution could be just not opening any submenu. I'm now jumping a lot through documentation (fixing links) and having to constantly press back in menu to change to a different object is slowing me down. I don't think the submenu helps much, when there already is a separate "On this page" that is much easier to navigate (except it's doesn't behave correctly on phones - #2337).

[jonchurch]

These are great attention to detail, keep them coming! Lemme know if you want to reserve any of these to work on yourself, othewise I'll take a shot at the issues as I see them

[krzysdz]

I'm way behind schedule with other work and there's no way I can find time to fix things that do not require immediate attention. If I have time or something bothers me too much, I usually open a PR without creating an issue first, or immediately after creating it.

Today I wanted to quickly resolve problems shown by the link checker (old external URLs, rate limits, etc.), but instead found many broken internal links and usability issues that made testing and looking for correct links much more annoying (such as this one).