Android NDK version >= 23 requires nightly toolchain

[necrashter]

libgcc was removed in Android NDK version r23-beta3 and Rust was updated accordingly (see this issue). However, this change does not seem to be available in stable Rust yet (2023-03-04). This is should be mentioned in exporting for Android section.

I will make a PR for this but I'm not sure where we should mention it. My idea is to add a "Troubleshooting" section similar to "Errors you might encounter" in HTML5 export page. But I think it should be included at the start as well since users start following instructions before reading the troubleshooting.

[chitoyuu]

Thanks for the initiative!

But I think it should be included at the start as well since users start following instructions before reading the troubleshooting.

Very good point. I would perhaps do it as a blockquote "alert" like the "bit of context" one, right at the top, given how likely a user might run into this problem on the first attempt.

As this is expected to be a temporary issue, it would be good to note the time of writing and include a link to the upstream issue for context.