docs: add minimal example (#1114)

examples/minimal.rs

@@ -0,0 +1,44 @@
+//! # [Ratatui] Minimal example
+//!
+//! The latest version of this example is available in the [examples] folder in the repository.
+//!
+//! Please note that the examples are designed to be run against the `main` branch of the Github
+//! repository. This means that you may not be able to compile with the latest release version on
+//! crates.io, or the one that you have installed locally.
+//!
+//! See the [examples readme] for more information on finding examples that match the version of the
+//! library you are using.
+//!
+//! [Ratatui]: https://github.com/ratatui-org/ratatui
+//! [examples]: https://github.com/ratatui-org/ratatui/blob/main/examples
+//! [examples readme]: https://github.com/ratatui-org/ratatui/blob/main/examples/README.md
+
+use crossterm::{
+    event::{self, Event, KeyCode, KeyEventKind},
+    execute,
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+};
+use ratatui::{backend::CrosstermBackend, text::Text, Terminal};
+
+/// This is a bare minimum example. There are many approaches to running an application loop, so
+/// this is not meant to be prescriptive. See the [examples] folder for more complete examples.
+/// In particular, the [hello-world] example is a good starting point.
+///
+/// [examples]: https://github.com/ratatui-org/ratatui/blob/main/examples
+/// [hello-world]: https://github.com/ratatui-org/ratatui/blob/main/examples/hello_world.rs
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut terminal = Terminal::new(CrosstermBackend::new(std::io::stdout()))?;
+    enable_raw_mode()?;
+    execute!(terminal.backend_mut(), EnterAlternateScreen)?;
+    loop {
+        terminal.draw(|frame| frame.render_widget(Text::raw("Hello World!"), frame.size()))?;
+        if let Event::Key(key) = event::read()? {
+            if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
+                break;
+            }
+        }
+    }
+    disable_raw_mode()?;
+    execute!(terminal.backend_mut(), LeaveAlternateScreen)?;
+    Ok(())
+}