add image content types to PhysicalDir

crates/treehouse/src/vfs/physical.rs

@@ -99,6 +99,9 @@ fn guess_content_type(extension: &str) -> Option<&'static str> {
         "woff" => Some("font/woff2"),
         "svg" => Some("image/svg+xml"),
         "atom" => Some("application/atom+xml"),
+        "png" => Some("image/png"),
+        "webp" => Some("image/webp"),
+        "jpg" | "jpeg" => Some("image/jpeg"),
         _ => None,
     }
 }