Update README.md

README.md

@@ -18,7 +18,7 @@ ProtPlot exports the Ribbon plot:
 
 A ribbon plot is constructed from a `Vector{Backboner.Protein.Chain}`, which you can obtain from a PDB file using the exported `readpdb` function.
 For convenience, argument conversion methods are defined, so you can also pass:
-- a `3x3xL` array of residue backbone atom coordinates (N, Ca, C).
+- a `3x3xL` array of residue backbone atom coordinates (N, Ca, C), or a vector of these for each chain.
 - a PDB file path.
 
 ```julia