Outdated info in Compiling for the Web

**Your Godot version:**
4.6
**Issue description:**
With the release of emscripten 5.0.0 I think the requirements should be updated to say that 5+ wont work.
I was using godot 4.6 and compiled a gdextension with 5.0.0 and while it compiled the extension didnt work when I played in browser and it wasnt obvious what the issue was. It took a full day to realize that it was a version mismatch issue so hopefully adding that caveat will make it more obvious for others to help avoid the issue.

The section on gdextension says "The default export templates do not include GDExtension support" but they do if you download the official export templates and its only if you build the export template yourself that you need to worry about setting dlink to enable extension support. So its not technically wrong but it makes it sound like you have to make your own export template to use a gdextension which is incorrect

**URL to the documentation page:**
https://docs.godotengine.org/en/stable/engine_details/development/compiling/compiling_for_web.html