message: Fix package description for new README
diff: @@ -26,7 +26,7 @@ with open(os.path.join("include/drjit/fwd.h")) as f:
  with open(os.path.join(this_directory, 'README.rst'), encoding='utf-8') as f:
  long_description = f.read()
  -long_description = long_description[long_description.find('Introduction'):]
  +long_description = long_description[long_description.find('About this project'):]
  drjit_cmake_toolchain_file = os.environ.get("DRJIT_CMAKE_TOOLCHAIN_FILE", "")
  