added some API examples to the README

README.md

@@ -21,6 +21,72 @@ Here a short list of features:
 * Extensible framework for quickly developing new nodes at compile time
 * A comprehensive automated test suite
 
+## API Examples
+
+### Raw `NodeConfigurator` API
+
+This API is the most low level API provided by HexoDSP.
+It shows how to create nodes and connect them.
+The execution of the nodes in the audio thread is
+controlled by a `NodeProg`, which defines the order
+the nodes are executed in.
+
+This only showcases the non-realtime generation of audio
+samples. For a real time application of this library please
+refer to the examples that come with this library.
+
+    use hexosynth::*;
+
+    let (mut node_conf, mut node_exec) = new_node_engine();
+
+    node_conf.create_node(NodeId::Sin(0));
+    node_conf.create_node(NodeId::Amp(0));
+
+    let mut prog = node_conf.rebuild_node_ports();
+
+    node_conf.add_prog_node(&mut prog, &NodeId::Sin(0));
+    node_conf.add_prog_node(&mut prog, &NodeId::Amp(0));
+
+    node_conf.set_prog_node_exec_connection(
+        &mut prog,
+        (NodeId::Amp(0), NodeId::Amp(0).inp("inp").unwrap()),
+        (NodeId::Sin(0), NodeId::Sin(0).out("sig").unwrap()));
+
+    node_conf.upload_prog(prog, true);
+
+    let (out_l, out_r) = node_exec.test_run(0.1, false);
+
+### Hexagonal Matrix API
+
+This is a short overview of the API provided by the
+hexagonal Matrix API, which is the primary API used
+inside [HexoSynth](https://github.com/WeirdConstructor/HexoSynth).
+
+This only showcases the non-realtime generation of audio
+samples. For a real time application of this library please
+refer to the examples that come with this library.
+
+    use hexodsp::*;
+
+    let (node_conf, mut node_exec) = new_node_engine();
+    let mut matrix = Matrix::new(node_conf, 3, 3);
+
+
+    let sin = NodeId::Sin(0);
+    let amp = NodeId::Amp(0);
+    matrix.place(0, 0, Cell::empty(sin)
+                       .out(None, None, sin.out("sig")));
+    matrix.place(0, 1, Cell::empty(amp)
+                       .input(amp.inp("inp"), None, None));
+    matrix.sync().unwrap();
+
+    let gain_p = amp.inp_param("gain").unwrap();
+    matrix.set_param(gain_p, SAtom::param(0.25));
+
+    let (out_l, out_r) = node_exec.test_run(0.11, true);
+    // out_l and out_r contain two channels of audio
+    // samples now.
+
 ## State of Development
 
 As of 2021-05-18: The architecture and it's functionality have been mostly