This creates an FFI plugin project in the hello
folder with the following specialized content:

lib: The Dart code that defines the API of the plugin,
  and which calls into the native code using dart:ffi.

src: The native source code, and a CmakeFile.txt
  file for building that source code into a dynamic library.

platform folders (android, ios, windows, etc.): The
  build files for building and bundling the native code
  library with the platform application.

Step 2: Building and bundling native code

The pubspec.yaml specifies FFI plugins as follows:

plugin

platforms

some_platform

ffiPlugin

true

This configuration invokes the native build
for the various target platforms and bundles
the binaries in Flutter applications using these FFI plugins.