Utilize `<NuxtLink>` wherever appropiate

[Readpato]

Describe the feature

Nuxt has a built-in component called <NuxtLink> which handles internal and external URLs by itself. We should utilize it whenever possible.

See for example our components/Footer component were the component could be implemented multiple times.

Additional information

• Would you be willing to help implement this feature?

Final checks

• Read the code of conduct.
• Check existing issues.