Update CMake usage in README build instructions

Update CMake usage in README build instructions

CMake 3.14.0 released in March 2019 [1] added the command line config options
`-S <source-dir>` and `-B <build-dir>` and the build argument `--build <build-dir>` [2].
These options are universally valid independent of the build system used (`make`,
`nmake`, `ninja`, `MSBuild`,...), making the provided CMake commands more generic.

As reference Ubuntu 20.04 ships the CMake 3.16.3 [3] version.

- [1] https://gitlab.kitware.com/cmake/cmake/-/tags/v3.14.0
- [2] https://cmake.org/cmake/help/v3.14/release/3.14.html#command-line
- [3] https://packages.ubuntu.com/focal/cmake

Signed-off-by: NeroBurner <pyro4hell@gmail.com>