Update the package links on the docs home page

[oliverschuerch]

As a user browsing the design system docs, I would like to be linked over to a version specific branch/tag, when clicking on a package link on the home page.

Example
Current link: https://github.com/swisspost/design-system/tree/main/packages/styles
Updated link: https://github.com/swisspost/design-system/tree/release/v9/packages/styles

Tasks

• Generate the link based on the major version number that's already being read by the docs