Broken links on example

[MicaelJarniac]

ipywidgets/docs/source/examples/Using Interact.ipynb

Line 333 in 90c1c14

"Finally, if you need more granular control than that afforded by the abbreviation, you can pass a `ValueWidget` instance as the argument. A `ValueWidget` is a widget that aims to control a single value. Most of the widgets [bundled with ipywidgets](Widget%20List) inherit from `ValueWidget`. For more information, see [this section](Widget%20Custom.ipynb#DOMWidget,-ValueWidget-and-Widget) on widget types."

On that example, there are some broken links:

• https://render.githubusercontent.com/view/Widget%20Custom.ipynb#DOMWidget,-ValueWidget-and-Widget
• https://render.githubusercontent.com/view/Widget%20List

One of the broken links is related to a file deleted on #2677, and an alternative is being worked on in #2919.