new pattern: Contain Unsafety in Small Modules

patterns/unsafe-mods.md

@@ -1,4 +1,4 @@
-# Contain Unsafety in Small Modules
+# Contain unsafety in small modules
 
 ## Description
 
@@ -16,7 +16,7 @@ If you have `unsafe` code, create the smallest possible module that can uphold t
 
 ## Examples
 
-* The [`optional`](https://crates.io/crates/optional) crate has one unsafe module for converting a `&T` to either a slice of one `[T]` or an empty slice.
+* The [`toolshed`](https://docs.rs/toolshed) crate contains its unsafe operations in submodules, presenting a safe interface to users.
 * `std`s `String` class is a wrapper over `Vec<u8>` with the added invariant that the contents must be valid UTF-8. The operations on `String` ensure this behavior. However, users have the option of using an `unsafe` method to create a `String`, in which case the onus is on them to guarantee the validity of the contents.
 
 ## See also