Update make.jl

Author: ChrisRackauckas

docs/make.jl

@@ -118,6 +118,7 @@ makedocs(
         "https://github.com/SciML/ColPrac/blob/master/README.md",
         "https://github.com/SciML/DiffEqDevTools.jl/blob/master/src/ode_tableaus.jl",
         "https://github.com/SciML/DiffEqProblemLibrary.jl/blob/master/lib/BVProblemLibrary/src/BVProblemLibrary.jl",
+        "https://github.com/SciML/DiffEqProblemLibrary.jl/blob/master/lib/DDEProblemLibrary/src/DDEProblemLibrary.jl",
     ],
     doctest = false, clean = true,
     warnonly = [:missing_docs, :docs_block],