Update README.md

Author: pehamTom

README.md

@@ -12,3 +12,13 @@ If you have any questions, feel free to contact us via [[email protected]]
 ## System Requirements and Building
 
 The implementation is compatible with any C++17 compiler and a minimum CMake version of 3.14.
+
+To get the most out of this library it is recommended to have the GMP library installed.
+
+### Building tests
+
+From the project root, run:
+
+Configuration: `cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_ZX_TESTS=ON -S . -B build`
+
+Compiling: `cmake --build build --config Release --target zx_test`