catalog: review entries that look filed in the wrong category

[TMHSDigital]

Candidates (a judgement call; the category rules may intend some of these):

• nasa-3d-resources (subcategory models) -> 3d
• nasa-image-video-library -> video (only 6 entries there)
• Software in content categories: microsoft-movebox, meta-animated-drawings, rokoko-vision (animation); makehuman, charmorph, mpfb, vroid-studio (characters). Either move them to tools or state the "tools live next to their content" rule in catalog/README.md.
• HDRIs are split: poly-haven and open-hdri are in environment, blenderkit (hdri) is in 3d.