Introduce some new commands and reduce their names to mostly single letter

modules/synth/src/main/kotlin/io/smnp/ext/synth/SynthModule.kt

@@ -11,7 +11,7 @@ import org.pf4j.Extension
 class SynthModule : HybridModuleProvider("smnp.audio.synth") {
    override fun functions() = listOf(WaveFunction(), SynthFunction())
 
-   override fun files() = listOf("envelope.mus")
+   override fun files() = listOf("envelope.mus", "command.mus")
 
    override fun onModuleLoad(environment: Environment) {
       Synthesizer.init()

modules/synth/src/main/resources/command.mus

@@ -0,0 +1,15 @@
+function o(overtones: list<float>) {
+    return { overtones -> overtones };
+}
+
+function e(envelope: map<string><>) {
+    return { envelope -> envelope };
+}
+
+function t(tuning: float) {
+    return { tuning -> tuning };
+}
+
+function bpm(bpm: int) {
+    return { bpm -> bpm };
+}