fix setup.py description

setup.py

@@ -1,13 +1,16 @@
-from setuptools import setup, find_packages
 from codecs import open
 from pathlib import Path
 
 import tomli
+from setuptools import setup, find_packages
 
 with open("pyproject.toml", "rb") as f:
     pyproject = tomli.load(f)
 
 
+def get_long_description() -> str:
+    return (Path(__file__).parent / "README.md").read_text()
+
 extra_requirements = {
     "readthedocs": [
         "furo",
@@ -26,6 +29,8 @@
     author="Snayt1k3",
     author_email="snayt1k3@gmail.com",
     description=pyproject["tool"]["poetry"]["description"],
+    long_description_content_type="text/markdown",
+    long_description=get_long_description(),
     url="https://github.com/Snayt1k3/shiki.py",
     classifiers=[
         "License :: OSI Approved :: MIT License",