message: readme: add build and using section
diff: @@ -26,9 +26,41 @@ IV) First class support for determistic applications (*blockchain*)
  - Support the bigint API
  - Support runtime metering in the interpreter
  -## Testing
  +## Building and using
  -To read about testing see [fizzy-spectests](./test/spectests/README.md).
  +Fizzy uses CMake as a build system:
  +```sh
  +$ mkdir build && cd build
  +$ cmake ..
  +$ cmake --build .
  +```
  +
  +This will build Fizzy as a library and since there is no public API
  +(the so called *embedder API* in WebAssembly) yet, this is not very useful.
  +
  +Building with the `FIZZY_TESTING` option will output a few useful utilities:
  +
  +```sh
  +$ mkdir build && cd build
  +$ cmake -DFIZZY_TESTING=ON ..
  +$ cmake --build .
  +```
  +
  +These utilities are as follows:
  +
  +### fizzy-bench
  +
  +This can be used to run benchmarks available in the `test/benchmarks` directory.
  +Read [this guide](./test/benchmarks/README.md) for a short introduction.
  +
  +### fizzy-spectests
  +
  +Fizzy is capable of executing the official WebAssembly tests.
  +Follow [this guide](./test/spectests/README.md) for using the tool.
  +
  +### fizzy-unittests
  +
  +This is the unit tests suite of Fizzy.
  ## License
  