`fa-lightbulb` -> `fa-user-plus`

- Use image overlays for the cards
- Use mix-blend-mode to make contrast high enough
- Show post image if one is defined

Changed You+HIFIS to HIFIS for YOU (to be discussed)

- Use default font instead of Hermann
- Reduce size by removing the image and some metainformation

This does not implement multilanguage support for the whole website, but
only for the content of specific pages.

- Also make use of the {%- syntax to reduce whitespace in the generated
HTML for the team member includes
- Fix alignment of title in the section part