Move UPLC dump into separate function + log event.

```
    Compiling aiken-lang/stdlib 43d8e740ffdf5febc59e51b7f0d5f8506115340c (examples/hello_world/build/packages/aiken-lang-stdlib)
    Compiling aiken-lang/hello_world 1.0.0 (examples/hello_world)
   Generating project's blueprint (examples/hello_world/plutus.json)
    Exporting UPLC (examples/hello_world/artifacts)
  ```

crates/aiken/src/cmd/new.rs

@@ -165,7 +165,7 @@ fn gitignore(root: &Path) -> miette::Result<()> {
         indoc! {
             r#"
                 # Aiken compilation artifacts
-                assets/
+                artifacts/
                 # Aiken's project working directory
                 build/
                 # Aiken's default documentation export

crates/aiken/src/lib.rs

@@ -94,11 +94,19 @@ impl telemetry::EventListener for Terminal {
             telemetry::Event::WaitingForBuildDirLock => {
                 println!("{}", "Waiting for build directory lock ...".bold().purple());
             }
+            telemetry::Event::DumpingUPLC { path } => {
+                println!(
+                    "{} {} ({})",
+                    "    Exporting".bold().purple(),
+                    "UPLC".bold(),
+                    path.display().bright_blue()
+                );
+            }
             telemetry::Event::GeneratingBlueprint { path } => {
                 println!(
                     "{} {} ({})",
                     "   Generating".bold().purple(),
-                    "contract blueprint".bold(),
+                    "project's blueprint".bold(),
                     path.display().bright_blue()
                 );
             }
@@ -112,7 +120,7 @@ impl telemetry::EventListener for Terminal {
             telemetry::Event::GeneratingUPLCFor { name, path } => {
                 println!(
                     "{} {}.{{{}}}",
-                    "   Generating Untyped Plutus Core for".bold().purple(),
+                    "   Generating UPLC for".bold().purple(),
                     path.to_str().unwrap_or("").blue(),
                     name.bright_blue(),
                 );