Add simplified hello world example

README.markdown

@@ -2,14 +2,30 @@
 
 **Ultra hyper turbo cyber mega extra über experimental!!!**
 
-## Compiling and running the demo
+![Hello world](hello_world.png)
+
+```rust
+frame.window()
+    .name(im_str!("Hello world"))
+    .size((300.0, 100.0), ImGuiSetCond_FirstUseEver)
+    .build(|| {
+        frame.text(im_str!("Hello world!"));
+        frame.text(im_str!("This...is...imgui-rs!"));
+        frame.separator();
+        let mouse_pos = frame.imgui().mouse_pos();
+        frame.text(im_str!("Mouse Position: ({:.1},{:.1})", mouse_pos.0, mouse_pos.1));
+    })
+```
+
+## Compiling and running the demos
 
     git clone https://github.com/Gekkio/imgui-rs
     cd imgui-rs
     git submodule update --init --recursive
     cargo test
 
-    target/debug/test_window
+    target/debug/examples/hello_world
+    target/debug/examples/test_window
 
 ## License
 

examples/hello_world.rs

@@ -0,0 +1,37 @@
+#[macro_use]
+extern crate glium;
+#[macro_use]
+extern crate imgui;
+extern crate time;
+
+use imgui::*;
+
+use self::support::Support;
+
+mod support;
+
+const CLEAR_COLOR: (f32, f32, f32, f32) = (1.0, 1.0, 1.0, 1.0);
+
+fn main() {
+    let mut support = Support::init();
+
+    loop {
+        let active = support.render(CLEAR_COLOR, |frame| {
+            hello_world(frame)
+        });
+        if !active { break }
+    }
+}
+
+fn hello_world<'a>(frame: &Frame<'a>) -> bool {
+    frame.window()
+        .name(im_str!("Hello world"))
+        .size((300.0, 100.0), ImGuiSetCond_FirstUseEver)
+        .build(|| {
+            frame.text(im_str!("Hello world!"));
+            frame.text(im_str!("This...is...imgui-rs!"));
+            frame.separator();
+            let mouse_pos = frame.imgui().mouse_pos();
+            frame.text(im_str!("Mouse Position: ({:.1},{:.1})", mouse_pos.0, mouse_pos.1));
+        })
+}