build: add CMake build system and README

[Ziminli]

TL;DR
This PR transitions the project from manual compilation to a structured CMake build system and adds a correspondingREADME.md.

Key Changes

• CMake Build System: add the CMake build system that can systematically build the project, both the examples and the shared library file.
• README: add the README for this project, which currently simply introduce the project and provides the basic guides to configure and build the project as well as run the example programs.

Future Work

• Continue enriching and refining the README.md with more details