[ADD] doc: new theme

Pretty much completely rewritten theme with custom HTML translator and a
few parts of the old theme extracted to their own extensions.

Banner images thought not to be that huge after all, and not worth the
hassle of them living in a different repository.

co-authored with @stefanorigano

1 files changed, 0 insertions, 0 deletions

diff --git a/doc/howtos/theme_tutorial_assets/img/functionalities.jpg b/doc/howtos/theme_tutorial_assets/img/functionalities.jpg
new file mode 100755
index 00000000000..dfe9b8d62d8
--- /dev/null
+++ b/doc/howtos/theme_tutorial_assets/img/functionalities.jpg