Allow unused on Writable trait

Or else it pops up every time we run the linter.

korangar/src/loaders/archive/mod.rs

@@ -21,6 +21,7 @@ pub enum ArchiveType {
 }
 
 /// A common trait to all writable archives.
+#[allow(unused)]
 pub trait Writable {
     fn create(&mut self) {}