Merge pull request #115 from tnull/2023-05-swap-out-builder

Move `Builder` to own module, allow for shared runtime reference.

Author: tnull

README.md

@@ -18,7 +18,7 @@ use ldk_node::bitcoin::Network;
 use std::str::FromStr;
 
 fn main() {
-	let builder = Builder::new();
+	let mut builder = Builder::new();
 	builder.set_network(Network::Testnet);
 	builder.set_esplora_server("https://blockstream.info/testnet/api".to_string());
 	builder.set_gossip_source_rgs("https://rapidsync.lightningdevkit.org/testnet/snapshot".to_string());