Remove unused quickstart link

TheZoq2 · TheZoq2 · commit cc66906ab8a1 · 2020-06-20T12:17:33.000+02:00
diff --git a/src/lib.rs b/src/lib.rs
@@ -45,9 +45,6 @@
 //! * F, G => `xl` feature
 //!
 //!
-//!
-//! [cortex-m-quickstart]: https://docs.rs/cortex-m-quickstart/0.3.1
-//!
 //! ## Usage examples
 //!
 //! See the [examples] folder.
