org card: add virig-5imus-4cams + aruco; 3-way community on-ramps; 14 datasets

org card: link sensor/dataset wiki

org card: Blackfly model filled (BFS-U3-16S2M)

org card: drop static-template index.html/style.css, add card frontmatter

organization card: about, repos, datasets-at-a-glance, citation

initial commit