Broken links for class members main body vs sidebar

[kevmoo]

See dart-lang/web#274

From @vsmenon

If I go here:

https://pub.dev/documentation/web/latest/web/Node-extension-type.html

and click on appendChild under METHODS on the right, I get a 404 error.

Not sure if this is a general bug with extension types.

From @kevmoo

Weird!

https://pub.dev/documentation/web/latest/web/Node/appendChild.html in the
main body
https://pub.dev/documentation/web/web/Node/appendChild.html on the sidebar

[kevmoo]

CC @srawlins

[srawlins]

I can reproduce this with local testing. Fix coming.