chore: update description

Author: Chi-En Wu

setup.cfg

@@ -4,7 +4,7 @@ version = 0.1.3
 license = MIT
 author = Chi-En Wu
 author_email = jason.wu@hahow.in
-description = Mypy plugin and stubs for Pika
+description = PEP-484 stubs for Pika
 long_description = file:README.md
 long_description_content_type = text/markdown
 url = https://github.com/hahow/pika-stubs