Update documentation

doc/profiles.md

@@ -41,7 +41,7 @@ All these options are named `ROBOTOLOGY_ENABLE_<profile>` .
 
 | CMake Option | Description | Main packages included | Default Value | Profile-specific documentation |
 |:------------:|:-----------:|:---------------------:|:-------------:|:----:|
-| `ROBOTOLOGY_ENABLE_CORE` | The core robotology software packages, necessary for most users. | [`YARP`](https://github.com/robotology/yarp), [`ICUB`](https://github.com/robotology/icub-main), [`ICUBcontrib`](https://github.com/robotology/icub-contrib-common), [`icub-models`](https://github.com/robotology/icub-models) and  [`robots-configurations`](https://github.com/robotology/robots-configuration). [`GazeboYARPPlugins`](https://github.com/robotology/GazeboYARPPlugins) and [`icub-gazebo`](https://github.com/robotology/icub-gazebo) if the `ROBOTOLOGY_USES_GAZEBO` option is enabled. | `ON` | [Documentation on Core profile.](#core) |
+| `ROBOTOLOGY_ENABLE_CORE` | The core robotology software packages, necessary for most users. | [`YARP`](https://github.com/robotology/yarp), [`ICUB`](https://github.com/robotology/icub-main), [`ICUBcontrib`](https://github.com/robotology/icub-contrib-common), [`icub-models`](https://github.com/robotology/icub-models) and  [`robots-configurations`](https://github.com/robotology/robots-configuration). [`GazeboYARPPlugins`](https://github.com/robotology/GazeboYARPPlugins) and [`icub-gazebo`](https://github.com/robotology/icub-gazebo) if the `ROBOTOLOGY_USES_GAZEBO` option is enabled. [`gym-ignition`](https://github.com/robotology/gym-ignition) if the `ROBOTOLOGY_USES_IGNITION` option is enabled. | `ON` | [Documentation on Core profile.](#core) |
 | `ROBOTOLOGY_ENABLE_ROBOT_TESTING` | The robotology software packages related to robot testing. |  [`RobotTestingFramework`](https://github.com/robotology/robot-testing-framework), [`icub-tests`](https://github.com/robotology/icub-tests), [`blocktest`](https://github.com/robotology/blocktest) and [`blocktest-yarp-plugins`](https://github.com/robotology/blocktest-yarp-plugins) | `OFF` | [Documentation on Robot Testing profile.](#robot-testing)  |
 | `ROBOTOLOGY_ENABLE_DYNAMICS` | The robotology software packages related to balancing, walking and force control. | [`iDynTree`](https://github.com/robotology/idyntree), [`blockfactory`](https://github.com/robotology/blockfactory), [`wb-Toolbox`](https://github.com/robotology/wb-Toolbox), [`whole-body-controllers`](https://github.com/robotology/whole-body-controllers), [`walking-controllers`](https://github.com/robotology/walking-controllers), [`matio-cpp`](https://github.com/dic-iit/matio-cpp), [`bipedal-locomotion-framework`](https://github.com/dic-iit/bipedal-locomotion-framework). | `OFF` | [Documentation on Dynamics profile.](#dynamics)  |
 | `ROBOTOLOGY_ENABLE_DYNAMICS_FULL_DEPS` | Optional dependencies for [`bipedal-locomotion-framework`](https://github.com/dic-iit/bipedal-locomotion-framework). | [`manif`](https://github.com/artivis/manif), [`qhull`](https://github.com/qhull/qhull), [`casadi`](https://github.com/casadi/casadi). [`CppAD`](https://github.com/coin-or/CppAD). | `OFF` | [Documentation on Dynamics full deps profile.](#dynamics-full-deps)  |
@@ -60,7 +60,8 @@ The dependencies CMake options specify if the packages dependending on something
 
 | CMake Option | Description | Default Value | Dependency-specific documentation |
 |:------------:|:-----------:|:-------------:|:---------------------------------:|
-| `ROBOTOLOGY_USES_GAZEBO`  | Include software and plugins that depend on the [Gazebo simulator](http://gazebosim.org/).  | `ON` on Linux and macOS, `OFF` on Windows   | [Documentation on Gazebo dependency.](#gazebo) |
+| `ROBOTOLOGY_USES_GAZEBO`  | Include software and plugins that depend on the [Gazebo Classic simulator](http://gazebosim.org/).  | `ON` on Linux and macOS, `OFF` on Windows   | [Documentation on Gazebo Classic dependency.](#gazebo) |
+| `ROBOTOLOGY_USES_IGNITION` | Include software that depend on the [Ignition Gazebo](ignitionrobotics.org/). | `OFF` | [Documentation on Ignition Gazebo dependency.](#ignition) |
 | `ROBOTOLOGY_USES_MATLAB`  | Include software and plugins that depend on the [Matlab](https://mathworks.com/products/matlab.html). | `OFF` | [Documentation on MATLAB dependency.](#matlab) |
 | `ROBOTOLOGY_USES_OCTAVE`  | Include software and plugins that depend on [Octave](https://www.gnu.org/software/octave/).  | `OFF` |  [Documentation on Octave dependency.](#octave) |
 | `ROBOTOLOGY_USES_PYTHON`  | Include software that depends on [Python](https://www.python.org/).  | `OFF` |  [Documentation on Python dependency.](#python) |
@@ -228,6 +229,17 @@ the correct enviroment variables as documented in [`robotology-superbuild-depend
 ### Check the installation
 Follow the steps in https://github.com/robotology/icub-gazebo#usage and/or https://github.com/robotology/icub-models#use-the-models-with-gazebo to check if the Gazebo-based iCub simulation works fine.
 
+## Ignition
+Support for this dependency is enabled by the `ROBOTOLOGY_USES_IGNITION` CMake option.
+This option is set to `OFF` on all platforms as it is still experimental.
+
+### System Dependencies
+Follow the official instructions to install Ignition on your platform, available at https://ignitionrobotics.org/docs.
+
+Different Ignition distributions can be installed alongside. 
+The projects included in the superbuild might require different distributions. 
+From the superbuild point of view, we currently do not allow enabling projects that only support a specific Ignition distribution, therefore all required distributions have to be found in the system.
+
 ## MATLAB
 Support for this dependency is enabled by the `ROBOTOLOGY_USES_MATLAB` CMake option.