Docs update to new CI and theme
This MR changes the documentation build process to use the new theme and build jobs from https://git.kontron-electronics.de/sw/ked/docs/mkdocs-ked. The docs are now built and deployed as part of the main public docs repo: https://git.kontron-electronics.de/sw/ked/docs/docs. It's still possible to build the BSP docs standalone for testing.
Edited by Frieder Schrempf