minor doc correction

Author: franckgaga

docs/src/manual/linmpc.md

@@ -80,8 +80,10 @@ These are the integrators for the unmeasured plant disturbances, and they are au
 added to the model outputs by default if feasible (see [`SteadyKalmanFilter`](@ref)
 for details).
 
-[^1]: We could have use an [`InternalModel`](@ref) structure to avoid state estimator design.
-    It was tested on the example of this page and it gives similar results.
+[^1]: We could have use an [`InternalModel`](@ref) structure with
+    `mpc = LinMPC(InternalModel(model), Hp=15, Hc=2, Mwt=[1, 1], Nwt=[0.1, 0.1])` to avoid
+    state estimator design . It was tested on the example of this page and it gives similar
+    results.
 
 Before closing the loop, we call [`initstate!`](@ref) with the actual plant inputs and
 measurements to ensure a bumpless transfer. Since `model` simulates our plant here, its