add StatsPlots dependency to docs

Author: TorkelE

docs/Project.toml

@@ -40,6 +40,7 @@ SciMLBase = "0bca4576-84f4-4d90-8ffe-ffa030f20462"
 SciMLSensitivity = "1ed8b502-d754-442c-8d5d-10ac956f44a1"
 SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
+StatsPlots = "f3b207a7-027a-5e70-b257-86293d7955fd"
 SteadyStateDiffEq = "9672c7b4-1e72-59bd-8a11-6ac3964bc41f"
 StochasticDiffEq = "789caeaf-c7a9-5a7d-9973-96adeb23e2a0"
 StructuralIdentifiability = "220ca800-aa68-49bb-acd8-6037fa93a544"
@@ -86,6 +87,7 @@ SciMLBase = "2.46"
 SciMLSensitivity = "7.60"
 SpecialFunctions = "2.4"
 StaticArrays = "1.9"
+StatsPlots = "0.15.7"
 SteadyStateDiffEq = "2.2"
 StochasticDiffEq = "6.65"
 StructuralIdentifiability = "0.5.11"