Vendor dependencies

Let's see how I like this workflow.

vendor/tui/examples/demo/main.rs

@@ -0,0 +1,31 @@
+mod app;
+#[cfg(feature = "crossterm")]
+mod crossterm;
+#[cfg(feature = "termion")]
+mod termion;
+mod ui;
+
+#[cfg(feature = "crossterm")]
+use crate::crossterm::run;
+#[cfg(feature = "termion")]
+use crate::termion::run;
+use argh::FromArgs;
+use std::{error::Error, time::Duration};
+
+/// Demo
+#[derive(Debug, FromArgs)]
+struct Cli {
+    /// time in ms between two ticks.
+    #[argh(option, default = "250")]
+    tick_rate: u64,
+    /// whether unicode symbols are used to improve the overall look of the app
+    #[argh(option, default = "true")]
+    enhanced_graphics: bool,
+}
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let cli: Cli = argh::from_env();
+    let tick_rate = Duration::from_millis(cli.tick_rate);
+    run(tick_rate, cli.enhanced_graphics)?;
+    Ok(())
+}