The goal of this commit is to propose a first step towards a new
`.. card::` directive for the toctrees. This is a first design
proposition for this new card component in raw html for the fallback
page `howtos.rst`
The long term objective is to redesign the toctrees by implementing card
components, clearer toctree list design and custom html pages.
Related to task-3059229
X-original-commit: c59663f252
53035435f9