feat: new fmt command and pretty printing works

crates/cli/src/args.rs

@@ -31,6 +31,9 @@ pub enum UplcCommand {
         #[clap(short, long)]
         out: Option<String>,
     },
+    Fmt {
+        input: PathBuf,
+    },
 }
 
 impl Default for Args {

crates/cli/src/main.rs

@@ -47,6 +47,15 @@ fn main() -> anyhow::Result<()> {
                     fs::write(&out_name, &bytes)?;
                 }
             }
+            UplcCommand::Fmt { input } => {
+                let code = std::fs::read_to_string(&input)?;
+
+                let program = parser::program(&code)?;
+
+                let pretty = program.to_pretty();
+
+                fs::write(&input, pretty)?;
+            }
             UplcCommand::Unflat { input, print, out } => {
                 let bytes = std::fs::read(&input)?;