doc(typed-uuid): add footnotes about new_unchecked

Author: ThinkerDreamer

benzina/src/typed_uuid.rs

@@ -4,10 +4,9 @@
 /// generates code which implements many useful traits, including the ones needed to work with
 /// [`diesel`].
 ///
-/// The generated structs do not expose any method or trait to create an arbitrary instance, in
+/// The generated structs do not expose any method or trait to create an arbitrary instance[^See note], in
 /// order to provide the guarantee that the `UUID` is valid. However, it is possible to choose to
 /// add traits and methods to customize the behavior.
-///
 #[cfg_attr(
     not(feature = "example-generated"),
     doc = "To see the documentation of a generated typed `UUID`, consider re-building the \
@@ -48,7 +47,7 @@
 /// }
 /// ```
 ///
-/// Keep in mind that there is no way to construct an instance unless the instantiation is done
+/// Keep in mind that there is no way[^See note] to construct an instance unless the instantiation is done
 /// inside the module containing the new type or a submodule of it:
 ///
 /// ```compile_fail,E0603
@@ -62,6 +61,9 @@
 /// let foo = inner::Foo(Uuid::default());
 /// //               ^^^ private tuple struct constructor
 /// ```
+///
+/// [^See note]: There is no way in normal usage to construct an instance. The exception is with the
+/// `new_unchecked` method, which is intended for special cases, such as testing.
 #[macro_export]
 macro_rules! typed_uuid {
     (