Try to install class on Github

docs/src/comparison.md

@@ -8,4 +8,27 @@ TODO
 | **Modularity**           | Every component is fully modular                     | Class-based for simple models | Requires raw code modification in many places               |
 | **Approximations**       | None                                                 | Mandatory (?)                 | Mandatory (?)                                               |
 | **Speed**                | Fast                                                 | Faster                        | Fastest                                                     |
-| **Sensitivity analysis** | Automatic differentiation                            | Finite differences            | Finite differences                                          |
+| **Sensitivity analysis** | Automatic differentiation                            | Finite differences            | Finite differences                                          |
+
+## Accuracy comparison with CLASS
+
+```@example class
+run(`make --version`)
+```
+
+```@example class
+run(`cc --version`)
+```
+
+```@example class
+run(`git clone --depth 1 https://github.com/lesgourg/class_public`)
+run(`make --directory class_public class`)
+```
+
+```@example class
+isdir(`class_public`)
+```
+
+```@example class
+isfile(`class_public/class`)
+```