RUSTSEC-2019-0031: add link to spinning-rs in description (#336)

Author: tarcieri

crates/spin/RUSTSEC-2019-0031.toml

@@ -8,11 +8,12 @@ url = "https://github.com/mvdnes/spin-rs/commit/7516c80"
 description = """
 The author of the `spin` crate does not have time or interest to maintain it.
 
-Consider the following alternatives (both of which support `no_std`):
+Consider the following alternatives (all of which support `no_std`):
 
 - [`conquer-once`](https://github.com/oliver-giersch/conquer-once)
 - [`lock_api`](https://crates.io/crates/lock_api) (a subproject of `parking_lot`)
   - [`spinning_top`](https://github.com/rust-osdev/spinning_top) spinlock crate built on `lock_api`
+- [`spinning`](https://github.com/4lDO2/spinning-rs)
 """
 
 [versions]