message: Add testing note to README.md
diff: @@ -82,6 +82,9 @@ An example can be found in the [`test_install`](test_install/CMakeLists.txt).
  Various examples are available for you to understand and play with Ginkgo within the `examples/` directory. They can be compiled by passing the `-DGINKGO_BUILD_EXAMPLES=ON` to the cmake command. Documentation for the examples is available within the `doc/` folder in each of the example directory and a commented code with explanations can found in the [online documentation](https://ginkgo-project.github.io/ginkgo/doc/develop/Examples.html).
  +### Ginkgo Testing
  +
  +Ginkgo does comprehensive unit tests using Google Tests. These tests are enabled by default and can be disabled if necessary by passing the `-DGINKGO_BUILD_TESTS=NO` to the cmake command. More details about running tests can be found in the [TESTING.md page](./TESTING.md).
  ### Running the benchmarks
  