Fix tutorial-nlp: add using NLPModelsIpopt for OptimalControl.Ipopt solver

Author: ocots

Project.toml

@@ -1,7 +1,7 @@
 name = "Tutorials"
 uuid = "cb10daa6-a5e5-4c25-a171-ae181b8ea3c9"
 authors = ["Olivier Cots <olivier.cots@toulouse-inp.fr>"]
-version = "0.3.2"
+version = "0.4.0"
 
 [compat]
 julia = "1.10"

docs/src/tutorial-nlp.md

@@ -1,7 +1,7 @@
 # [NLP and DOCP manipulations](@id tutorial-nlp)
 
 ```@meta
-Draft = true
+Draft = false
 CurrentModule =  OptimalControl
 ```
 
@@ -91,6 +91,7 @@ We have two approaches to solve the NLP problem.
 We can create an OptimalControl solver strategy and use it to solve the NLP:
 
 ```@example main-nlp
+using NLPModelsIpopt
 solver = OptimalControl.Ipopt(print_level=5, tol=1e-8, mu_strategy="adaptive")
 nlp_sol = solve(nlp, solver; display=true)
 nothing # hide