Apply a bunch of clippy lints

src/main.rs

@@ -1,6 +1,7 @@
 use std::{fs::File, io::BufWriter, path::PathBuf};
 
 use clap::{Parser, Subcommand};
+use coster_rs::CreateProductInputs;
 
 #[derive(Parser)]
 #[command(name = "coster-rs")]
@@ -177,11 +178,13 @@ fn main() -> anyhow::Result<()> {
             output,
         } => coster_rs::create_products(
             &mut csv::Reader::from_path(definitions)?,
-            &mut csv::Reader::from_path(encounters)?,
-            &mut csv::Reader::from_path(services)?,
-            &mut csv::Reader::from_path(transfers)?,
-            &mut csv::Reader::from_path(procedures)?,
-            &mut csv::Reader::from_path(diagnoses)?,
+            CreateProductInputs {
+                encounters: csv::Reader::from_path(encounters)?,
+                services: csv::Reader::from_path(services)?,
+                transfers: csv::Reader::from_path(transfers)?,
+                procedures: csv::Reader::from_path(procedures)?,
+                diagnoses: csv::Reader::from_path(diagnoses)?,
+            },
             &mut csv::Writer::from_path(output)?,
             1000000,
         ),