Add information to set Windows proxy environment variables

README.md

@@ -5,11 +5,19 @@ This provides a set of scripts and a configuration file allowing to build TELEMA
 ## Prerequisites:
 
 - **Git**: download it from [gitforwindows.org](https://gitforwindows.org/) and install it with the LFS extension.
-- **CMake**: install the latest 64 bits version available from [cmake.org](https://cmake.org), and be sure that CMake is added to your PATH environment variable.<br>
-Note: to install CMake without administrator rights, you need to download and extract the zip file.
+- **CMake**: install the latest 64 bits version available from [cmake.org](https://cmake.org), and ensure that CMake `bin` directory is added to your `PATH` environment variable.<br>
+Note: to install CMake without administrator rights, you need to download and extract the zip file and set your `PATH` manually.
 - **Mingw-w64**: download the 8.5 version from [winlibs](https://github.com/brechtsanders/winlibs_mingw/releases/download/8.5.0-9.0.0-r1/winlibs-x86_64-posix-seh-gcc-8.5.0-mingw-w64-9.0.0-r1.zip) and extract it to `C:\`.<br>
 Note: if you don't install Mingw-w64 in `C:\`, you will need to add its `bin` directory to your `PATH`.
 
+## Proxy configuration
+
+If your computer is behind a proxy, you also need to set Windows proxy environment variables, such as below:
+```
+C:\>set http_proxy=http://vip-users.proxy.edf.fr:3131
+C:\>set https_proxy=http://vip-users.proxy.edf.fr:3131
+```
+
 ## Building and installing TELEMAC-MASCARET dependencies
 
 TELEMAC-MASCARET can be built with or without several dependencies, which are listed below: