ReDNATCO plugin stage 4

src/apps/rednatco/idents.ts

src/apps/rednatco/index.html

src/apps/rednatco/index.tsx

src/apps/rednatco/reference-conformers-pdbs.ts

src/apps/rednatco/reference-conformers.ts

src/apps/rednatco/step.ts

src/apps/rednatco/superpose.ts

src/apps/rednatco/util.ts