Wasmer: Rendering of the C/C++ API homepage

[ShalokShalom]

On modern mobile, the sidebar automatically opens up and seems to take half the screen:

[Hywan]

I reckon you can fold the sidebar. But the layout wasn't aimed to be used on a mobile. I'll check that as soon as I've time.

[Hywan]

Our C documentation is now generated with rustdoc thanks to inline-c (see how to get testable and runnable C examples within rustdoc).

You can check https://github.com/wasmerio/wasmer/pull/1795 and https://github.com/wasmerio/wasmer/pull/1930 to get further information.

So, Doxygen is going to be removed from our toolbox. Consequently, I'm closing this issue :-).