This function adds a column to the internal rl 'map' used to map all receptor and receptor complexes to all ligand and ligand complexes.
Examples
example(create_rl_map_cellphonedb, echo = FALSE)
lr_name <- data.frame("abbrev" = c("L", "R"), "full" = c("Ligand", "Receptor"))
rl_map_expanded <- add_rl_column(map = rl_map_tiny, map_ref = "type_A",
conv = lr_name, new_name = "type_A_full")