move examples to main repo so we can include_str them for publishing (#993)

* move exampels to main repo so we can include_str them for publishing

* update CI to not break examples

subxt/examples/constants_dynamic.rs

@@ -0,0 +1,17 @@
+use subxt::{OnlineClient, PolkadotConfig};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Create a client to use:
+    let api = OnlineClient::<PolkadotConfig>::new().await?;
+
+    // A dynamic query to obtain some contant:
+    let constant_query = subxt::dynamic::constant("System", "BlockLength");
+
+    // Obtain the value:
+    let value = api.constants().at(&constant_query)?;
+
+    println!("Constant bytes: {:?}", value.encoded());
+    println!("Constant value: {}", value.to_value()?);
+    Ok(())
+}