feat: add secrets

__security/secrets/src/main.rs

@@ -0,0 +1,12 @@
+use secrets::Secret;
+
+fn main() {
+    Secret::<[u8; 16]>::random(|s| {
+        // use `s` as if it were a `&mut [u8; 16]`
+        //
+        // the memory is `mlock(2)`ed and will be zeroed when this closure
+        // exits
+        println!("{:?}", s);
+        println!("{:?}", *s);
+    });
+}