Add export command

brood/src/commands/export.rs

@@ -0,0 +1,17 @@
+use std::{io, path::PathBuf};
+
+use crate::data::Data;
+
+#[derive(Debug, clap::Parser)]
+pub struct Cmd {
+    out: PathBuf,
+}
+
+impl Cmd {
+    pub fn run(self, data: Data) -> io::Result<()> {
+        println!(">> Export");
+        data.write_to_file(&self.out)?;
+
+        Ok(())
+    }
+}