add comparison with direct sol

Author: ocots

docs/make.jl

@@ -112,7 +112,7 @@ cp(joinpath(@__DIR__, "Project.toml"), joinpath(@__DIR__, "src", "assets", "Proj
 repo_url = "github.com/control-toolbox/OptimalControl.jl"
 
 makedocs(;
-    draft=true, # if draft is true, then the julia code from .md is not executed
+    draft=false, # if draft is true, then the julia code from .md is not executed
     # to disable the draft mode in a specific markdown file, use the following:
     # ```@meta
     # Draft = false

docs/src/manual-flow-ocp.md

@@ -2,7 +2,6 @@
 
 ```@meta
 CollapsedDocStrings = false
-Draft = false
 ```
 
 In this tutorial, we explain the `Flow` function, in particular to compute flows from an optimal control problem.