Each folder explains itself, and the listing stays beside you

A folder with an index.md or a README.md opens it on the right of its listing, and the analysis folder shows its generated index there. Open a document and the listing of its folder stays on the left in a narrow column with it marked, and a .. row takes you up one folder, so the next file is one click away. A link to another document opens it from the folder it is written in, and the images of the folder open in a viewer you step through without leaving the page.