Krita.org is the central hub where people learn about Krita and download the latest version. It is powered by WordPress and hosted by KDE. The GIT repository that has the theme files is located here https://quickgit.kde.org/?p=websites%2Fkrita-org-theme.git
Docs.krita.org is the educational area for Krita. You can find it under the Learn area. It is powered by Sphinx.