Link Customization

**Is your feature request related to a problem?

The documentation shows how to customize nodes and it works brilliantly. I would also like to modify links, such as changing the fill color, adding an on-hover tool tip to display information etc.

**Describe the solution you'd like**

Include an example on how to modify links in documentation.

**Describe alternatives you've considered**

I tried modifying the original code but had little success.

**Additional context**

Thank you for this library! It is absolutely brilliant and easy to use. A few more examples can help beginners like me.