feat(setup.py): restructure extras_require options for clarity

Refactor the `extras_require` section in `setup.py` to simplify and clarify
the available options. Consolidate CPU and GPU requirements into single
"lite" and "full" options to streamline installation for users.

setup.py

@@ -32,9 +32,8 @@ if __name__ == '__main__':
         },
         install_requires=parse_requirements('requirements.txt'),  # 项目依赖的第三方库
         extras_require={
-            "gpu": ["paddleocr==2.7.3", "paddlepaddle-gpu"],
-            "cpu": ["paddleocr==2.7.3", "paddlepaddle"],
-            "full-cpu": ["unimernet", "matplotlib", "ultralytics", "paddleocr==2.7.3", "paddlepaddle"],
+            "lite": ["paddleocr==2.7.3", "paddlepaddle", "paddlepaddle-gpu"],
+            "full": ["unimernet", "matplotlib", "ultralytics", "paddleocr==2.7.3", "paddlepaddle", "paddlepaddle-gpu"],
         },
         description="A practical tool for converting PDF to Markdown",  # 简短描述
         long_description=long_description,  # 详细描述