Update README.md

README.md

@@ -8,6 +8,22 @@
 
 [![GitHub Actions Status](https://github.com/bokuweb/docx-rs/workflows/Continuous%20Integration/badge.svg)](https://github.com/bokuweb/docx-rs/actions)
 
-# Features
+## Example
+
+``` rust
+use docx_core::*;
+
+pub fn hello() -> Result<(), DocxError> {
+  let path = std::path::Path::new("./tests/output/hello.docx");
+  let file = std::fs::File::create(&path).unwrap();
+  Docx::new()
+    .add_paragraph(Paragraph::new().add_run(Run::new().add_text("Hello")))
+    .build()
+    .pack(file)?;
+  Ok(())
+}
+```
+
+## Features
 
 - [x] Paragraph