Use placeholder links in examples

Hi there, I noticed in the example usage for [Link](https://uikit.commercetools.com/?path=/docs/components-link-readme--props) we use `https://kanyetothe.com` as an example:


A quick check of the repo also indicates this link is being used in some tests.

For best practices, it's advised to link to https://www.example.com/, as this domain was explicitly set up for such purposes. Failing that, it should be changed to a domain under our control, such as https://commercetools.com/