Update README.md

README.md

@@ -736,6 +736,7 @@ See also [About Rust’s Machine Learning Community](https://medium.com/@autumn_
 * [oxide-auth](https://github.com/HeroicKatora/oxide-auth) — A OAuth2 server library, for use in combination with actix or other frontends, featuring a set of configurable and pluggable backends [![Build Status](https://api.cirrus-ci.com/github/HeroicKatora/oxide-auth.svg?branch=master)](https://cirrus-ci.com/github/HeroicKatora/oxide-auth)
 * [sgrust01/jwtvault](https://github.com/sgrust01/jwtvault) — Async library to manage and orchestrate JWT workflow  [![Build Status](https://api.travis-ci.org/sgrust01/jwtvault.svg?branch=master)](https://travis-ci.org/sgrust01/jwtvault)
 * [yup-oauth2](https://github.com/dermesser/yup-oauth2) — An oauth2 client implementation providing the Device, Installed and Service Account flows [![Build Status](https://api.travis-ci.org/dermesser/yup-oauth2.svg?branch=master)](https://travis-ci.org/dermesser/yup-oauth2)
+* [constantoine/totp-rs](https://github.com/constantoine/totp-rs) [[totp-rs](https://crates.io/crates/totp-rs)] — 2fa library to generate and verify TOTP-based tokens ![Build Status](https://github.com/constantoine/totp-rs/workflows/Rust/badge.svg)
 
 ### Automotive