Integrate with RiboDraw

[AntonPetrov]

R2DT should be able to use diagrams produced by RiboDraw as templates, similar to how it's done with XRNA-GT. This would enable a source of curated diagrams for RNAs with experimentally determined 3D structures. Looks like lots of people would find this useful.

It would be interesting to explore producing multiple diagrams for the same sequence. For example, an rRNA sequence can be visualised using CRW, RiboVision, or RiboDraw layouts.

CC @everyday847 @aspetr01