Fix: Enable serde/derive when enabling json5 feature

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

Cargo.toml

@@ -19,7 +19,7 @@ default = ["toml", "json", "yaml", "ini", "ron", "json5", "convert-case", "async
 json = ["serde_json"]
 yaml = ["yaml-rust"]
 ini = ["rust-ini"]
-json5 = ["json5_rs"]
+json5 = ["json5_rs", "serde/derive"]
 convert-case = ["convert_case"]
 preserve_order = ["indexmap", "toml/preserve_order", "serde_json/preserve_order", "ron/indexmap"]
 async = ["async-trait"]