Add simple serialization example (good starting point for no_std).

examples/simple_serialize.rs

@@ -0,0 +1,31 @@
+use edn_rs::Serialize;
+
+struct Foo<'a> {
+    value: u64,
+    say: &'a str,
+}
+
+impl Serialize for Foo<'_> {
+    fn serialize(&self) -> String {
+        format!("{{:value {}, :say {:?}}}", self.value, self.say)
+    }
+}
+
+fn serialize() -> String {
+    let say = "Hello, World!";
+    let foo = Foo {
+        value: 42,
+        say: say,
+    };
+
+    edn_rs::to_string(&foo)
+}
+
+fn main() {
+    println!("{}", serialize());
+}
+
+#[test]
+fn test_serialize() {
+    assert_eq!(serialize(), "{:value 42, :say \"Hello, World!\"}");
+}