Add a trivial example for rust-script.

Author: artob

examples

@@ -0,0 +1,21 @@
+#!/usr/bin/env rust-script
+//! This is free and unencumbered software released into the public domain.
+//!
+//! ```cargo
+//! [dependencies]
+//! protoflow = "0.2"
+//! ```
+
+use protoflow::{blocks::*, BlockResult};
+
+fn main() -> BlockResult {
+    System::run(|s| {
+        let greeting = s.const_string("Hello, world!");
+
+        let line_encoder = s.encode_lines();
+        s.connect(&greeting.output, &line_encoder.input);
+
+        let stdout = s.write_stdout();
+        s.connect(&line_encoder.output, &stdout.input);
+    })
+}