add simple examples for plot and print in doc

Author: ocots

.markdownlint.json

@@ -0,0 +1,4 @@
+{
+    "MD046": false,
+    "MD013": false
+}

docs/Project.toml

@@ -1,4 +1,5 @@
 [deps]
+CTParser = "32681960-a1b1-40db-9bff-a1ca817385d1"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 JLD2 = "033835bb-8acc-5ee8-8aae-3f567f8a3819"
 JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"

docs/src/plot.md

@@ -38,10 +38,46 @@ Order = [:module, :constant, :type, :function, :macro]
     julia> private_fun(x)
     ```
 
+## Simple example
+
+```@example
+using CTModels, Plots
+import CTParser: @def
+
+t0, tf, x0 = 0.0, 1.0, -1.0
+
+ocp = @def begin
+    t ∈ [t0, tf], time
+    x ∈ R, state
+    u ∈ R, control
+    x(t0) == x0
+    -Inf ≤ x(t) + u(t) ≤ 0, (mixed_con)
+    ẋ(t) == u(t)
+    ∫(0.5u(t)^2) → min
+end
+
+sol = CTModels.build_solution(
+    ocp,
+    collect(range(t0, tf; length=201)),
+    t -> x0 * exp(-t),
+    t -> -x0 * exp(-t),
+    Float64[],
+    t -> exp(t - tf) - 1;
+    objective = exp(-1) - 1,
+    iterations = 0,
+    constraints_violation = 0.0,
+    message = "",
+    status = :optimal,
+    successful = true,
+)
+
+plot(sol)
+```
+
 ## Documentation
 
 ```@autodocs
 Modules = [CTModelsPlots]
 Order = [:module, :constant, :type, :function, :macro]
 Pages = ["plot.jl", "plot_utils.jl", "plot_default.jl", "CTModelsPlots.jl"]
-```
+```

docs/src/print.md

@@ -8,10 +8,29 @@ Modules = [CTModels, Base]
 Order = [:module, :constant, :type, :function, :macro]
 ```
 
+## Simple example
+
+```@example
+using CTModels, Plots
+import CTParser: @def
+
+t0, tf, x0 = 0.0, 1.0, -1.0
+
+ocp = @def begin
+    t ∈ [t0, tf], time
+    x ∈ R, state
+    u ∈ R, control
+    x(t0) == x0
+    -Inf ≤ x(t) + u(t) ≤ 0, (mixed_con)
+    ẋ(t) == u(t)
+    ∫(0.5u(t)^2) → min
+end
+```
+
 ## Documentation
 
 ```@autodocs
 Modules = [CTModels]
 Order = [:module, :constant, :type, :function, :macro]
 Pages = ["print.jl"]
-```
+```