add simple example

crates/examples/examples/0001-simple.toml

+[settings]
+timeout = 1000
+
+[relaychain]
+default_image = "docker.io/parity/polkadot-sdk:latest"
+chain = "rococo-local"
+command = "polkadot"
+
+  [[relaychain.nodes]]
+  name = "alice"
+  args = [ "--alice", "-lruntime=debug,parachain=trace" ]
+
+  [[relaychain.nodes]]
+  name = "bob"
+  args = [ "--bob", "-lruntime=debug,parachain=trace" ]
+
+[[parachains]]
+id = 100
+addToGenesis = false
+
+  [parachains.collator]
+  name = "collator01"
+  image = "docker.io/parity/polkadot-sdk:latest"
+  command = "adder-collator"
+  args = [ "-lruntime=debug,parachain=trace" ]
+
+[types.Header]
+number = "u64"
+parent_hash = "Hash"
+post_state = "Hash"
\ No newline at end of file

crates/examples/examples/simple_network_example.rs

+use configuration::NetworkConfig;
+
+fn main() {
+
+    let load_from_toml =
+            NetworkConfig::load_from_toml("./0001-simple.toml").unwrap();
+
+    // let config = NetworkConfigBuilder::new()
+    //     .with_relaychain(|r| {
+    //         r.with_chain("rococo-local")
+    //             .with_node(|node| node.with_name("alice").with_command("polkadot"))
+    //     })
+    //     .build();
+
+    println!("{:?}", load_from_toml);
+}