setup.py: Add a description and long description.

This adds a short description and puts the contents from the README into
the long description.

This will be useful for packages that will end up on pypi.

setup.py

@@ -1,4 +1,5 @@
 from setuptools import setup
+from os import path
 
 try:
     from setuptools_rust import Binding, RustExtension
@@ -6,10 +7,21 @@ except ImportError:
     print("Please install setuptools-rust package")
     raise SystemExit(1)
 
+this_directory = path.abspath(path.dirname(__file__))
+with open(path.join(this_directory, 'README.md'), encoding='utf-8') as f:
+    long_description = f.read()
+
+
 setup(
     name="tantivy",
     version="0.10.1",
     rust_extensions=[RustExtension("tantivy.tantivy", binding=Binding.PyO3)],
     packages=["tantivy"],
+    description=("Python bindings for the Tantivy full-text search engine "
+                 "library"),
+    long_description=long_description,
+    long_description_content_type="text/markdown",
+    license="MIT",
+
     zip_safe=False,
 )