Complete skeleton dispatcher

- Complete the dispatcher for the 'introducer' and 'local' command. This
  is currently only a skeleton.
- The 'introducer list' command is added.

src/commands/introducer/remove.rs

@@ -0,0 +1,11 @@
+use anyhow::Result;
+
+use crate::cli::cli_args::IntroducerRemoveCommand;
+use crate::config::HuskConfigContainer;
+
+pub async fn dispatch(cmd: IntroducerRemoveCommand, _config: &HuskConfigContainer) -> Result<()> {
+    println!("remove");
+    println!("   {:?}", cmd.cert);
+    Ok(())
+}
+