Update nelson.jmd

Author: ChrisRackauckas

benchmarks/AstroChem/nelson.jmd

@@ -178,6 +178,9 @@ p1 = plot(sol1, vars = (0,11), lc=colors[1], legend = false, titlefontsize = 12,
 p2 = plot(sol2, vars = (0,11), lc=colors[2], legend = false, titlefontsize = 12, lw = 3, title = "HCO+ solved using FBDF")
 p3 = plot(sol3, vars = (0,11), lc=colors[3], legend = false, titlefontsize = 12, lw = 3, title = "HCO+ solved using lsoda")
 p4 = plot(sol4, vars = (0,11), lc=colors[4], legend = false, titlefontsize = 12, lw = 3, title = "HCO+ solved using lsoda with saveat")
+```
+
+```julia
 combined_plot = plot(p1, p2, p3, p4, layout=(4, 1), dpi = 600, pallete=:acton)
 ```