Add smooth scrolling when clicking on section links

### Description

This is a very minor improvement that could be made to the website, I noticed that when you click on a particular section, it automatically just takes you to that section. Works as intended, but You can easily get lost where you are, since it magically teleports you there. Adding smooth scrolling would help with this issue, and let the reader know where the page is taking them.

### Motivation
Mild UI improvements for the user.

### Collaboration
I can build this out. Or if someone wants to do it

### Additional Context
Example of the thing I'm talking about. It just snaps to that section, adding smooth scrolling would scroll the page to that section, so the reader doesn't get lost.

In der Issue wird keine Datei und kein Test genannt. Beginne damit, die Verarbeitung von Abschnittslinks auf der Website zu finden und das aktuelle Sprungverhalten zu reproduzieren; als abgeschlossen gilt die Aufgabe, wenn ein Klick auf einen Abschnittslink sichtbar zum Ziel scrollt, statt direkt dorthin zu springen.

Vom Indexierungsmodell aus dem Issue-Text verfasst.