Check broken images and mermaid graphs

[rmarquis]

It looks like the udpate to last mkdocs-material broke things:

• inlined icons (:simple-name:)
• mermaid graph orientation (see part 1)
• mermaid graph label on multilines

Mermaid 11 was introduced in the last mkdocs-material update. Investigate, and if not possible to fix, revert to the previous version for the time being.

[rmarquis]

See simple-icons/simple-icons#11236 for missing windows icons: Microsoft legal team requested that customized Microsoft icons be removed for legal branding issue.

They have been removed from the simple iconset, used by mkdocs-material.

Check and replace these missing icons. I think It should only be the windows icon.

[rmarquis]

As for the mermaid graph, it seems this is related to the latest update of mkdocs which now includes Mermaid 11. Changing the orientation of the messed up graphs (part 2) should be enough.

This issue is not visible in the currently deployed version, but will be once #200 is merged.
Change the orientation of the graph.