Rename --threads to --concurrency

And add alias to previous name

src/cli/args.rs

@@ -45,9 +45,9 @@ pub struct CliArgs {
     #[arg(short = 'p', long = "password", global = true)]
     pub password: Option<OsString>,
 
-    /// Concurrent working threads
-    #[arg(short = 'c', long, global = true)]
-    pub threads: Option<usize>,
+    /// Limit the amount of concurrent threads available
+    #[arg(short, long, visible_alias = "threads", global = true)]
+    pub concurrency: Option<usize>,
 
     // Ouch and claps subcommands
     #[command(subcommand)]
@@ -154,7 +154,7 @@ mod tests {
             format: None,
             // This is usually replaced in assertion tests
             password: None,
-            threads: None,
+            concurrency: None,
             cmd: Subcommand::Decompress {
                 // Put a crazy value here so no test can assert it unintentionally
                 files: vec!["\x00\x11\x22".into()],

src/commands/mod.rs

@@ -54,7 +54,7 @@ pub fn run(
     question_policy: QuestionPolicy,
     file_visibility_policy: FileVisibilityPolicy,
 ) -> crate::Result<()> {
-    if let Some(threads) = args.threads {
+    if let Some(threads) = args.concurrency {
         rayon::ThreadPoolBuilder::new()
             .num_threads(threads)
             .build_global()