feat: add download badges to README

- Add PyPI downloads badge to show monthly download statistics
- Add Crates.io downloads badge to display Rust crate downloads

Author: zTgx

README.md

@@ -4,7 +4,9 @@
 
 [![PyPI](https://img.shields.io/pypi/v/vectorless.svg)](https://pypi.org/project/vectorless/)
 [![Python](https://img.shields.io/pypi/pyversions/vectorless.svg)](https://pypi.org/project/vectorless/)
+[![PyPI Downloads](https://static.pepy.tech/badge/vectorless/month)](https://pepy.tech/projects/vectorless)
 [![Crates.io](https://img.shields.io/crates/v/vectorless.svg)](https://crates.io/crates/vectorless)
+[![Crates.io Downloads](https://img.shields.io/crates/d/vectorless.svg)](https://crates.io/crates/vectorless)
 [![Docs](https://docs.rs/vectorless/badge.svg)](https://docs.rs/vectorless)
 [![License](https://img.shields.io/badge/license-Apache--2.0-blue.svg)](LICENSE)
 [![Rust](https://img.shields.io/badge/rust-1.85%2B-orange.svg)](https://www.rust-lang.org/)