Add orx-time-operators with Envelope & LFO

orx-time-operators/README.md

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+# orx-time-operators
+
+A collection of time-sensitive functions aimed at controlling raw data over-time.
+
+## Usage
+
+Use the TimeOperators extension to `tick` the operators, making them advance in time.
+
+```kotlin
+extend(TimeOperators()) {
+    track(envelope, lfo)
+}
+```
+
+### Envelope
+
+```kotlin
+val size = Envelope(50.0, 400.0, 0.5, 0.5)
+
+if (frameCount % 80 == 0) {
+    size.trigger() // also accepts a new target value
+}
+
+drawer.circle(0.0, 0.0, size.value)
+```
+
+### LFO
+
+```kotlin
+val size = LFO(LFOWave.SINE) // default LFOWave.SAW
+
+val freq = 0.5
+val phase = 0.5
+
+drawer.circle(0.0, 0.0, size.sample(freq, phase))
+
+// or
+
+drawer.circle(0.0, 0.0, size.sine(freq, phase))
+```
+
+