feat(tracker/presets): new and tweaked presets from Reaby

The presets are also organized by their type into subfolders.

Closes #136

tracker/presets/PL/Sine pluck.yml

@@ -0,0 +1,28 @@
+name: PL Sine
+numvoices: 3
+units:
+    - type: envelope
+      id: 163
+      parameters: {attack: 39, decay: 60, gain: 71, release: 30, stereo: 0, sustain: 0}
+    - type: oscillator
+      id: 164
+      parameters: {color: 53, detune: 73, gain: 83, lfo: 0, phase: 14, shape: 27, stereo: 0, transpose: 88, type: 0, unison: 3}
+    - type: oscillator
+      id: 165
+      parameters: {color: 128, detune: 66, gain: 61, lfo: 0, phase: 64, shape: 100, stereo: 0, transpose: 88, type: 0, unison: 1}
+    - type: addp
+      id: 166
+      parameters: {stereo: 0}
+    - type: mulp
+      id: 167
+      parameters: {stereo: 0}
+    - type: pan
+      id: 168
+      parameters: {panning: 64, stereo: 0}
+    - type: delay
+      id: 169
+      parameters: {damp: 116, dry: 117, feedback: 23, notetracking: 0, pregain: 65, stereo: 1}
+      varargs: [12550, 24402, 21265, 32419]
+    - type: outaux
+      id: 172
+      parameters: {auxgain: 35, outgain: 32, stereo: 1}