fix: update usage of threads to be a minimum of five

Author: nh13

src/bin/commands/demux.rs

@@ -622,7 +622,7 @@ pub(crate) struct Demux {
     #[clap(long, short = 'd', default_value = "2")]
     min_mismatch_delta: usize,
 
-    /// The number of threads to use. Cannot be less than 3.
+    /// The number of threads to use. Cannot be less than 5.
     #[clap(long, short = 't', default_value = "8")]
     threads: usize,