Fix tabbed content bug in default js (#2538) (#2540)
Fix tabbed content bug in default js (#2538) (#2540)

* Fix tabbed content bug in default js

* Update docfx.js

dotnet/docfx,superyyrrzz/docfx,superyyrrzz/docfx,dotnet/docfx,superyyrrzz/docfx,dotnet/docfx