Add Module Presets page.

Presets.md

@@ -0,0 +1,40 @@
+# Module Presets
+
+![](images/presets.png)
+
+Factory module presets are a great tool for teaching and inspiring users of your Rack plugin.
+They store parameter values, as well as internal data from your `Module::dataToJson()` method if overridden.
+
+To include a factory module preset in your module, save a module preset file (`.vcvm`) to
+```
+<your plugin's root dir>/presets/<module slug>/<preset name>.vcvm
+```
+
+Module presets are sorted alphabetically by filename.
+However, (since Rack 2) if a filename begins with numerical digits followed by `_` (regex `/^\d+_/`), that prefix is not displayed to the user, so you can apply your own custom preset sorting order.
+For example, the above screenshot uses the following preset filenames.
+```
+/presets/DrumMachine/00_House.vcvm
+/presets/DrumMachine/01_House 2.vcvm
+/presets/DrumMachine/02_Techno.vcvm
+/presets/DrumMachine/03_IDM.vcvm
+/presets/DrumMachine/04_Moombah.vcvm
+/presets/DrumMachine/05_Lounge.vcvm
+```
+
+Presets can be edited with a text editor to update only a subset of parameters.
+For example, to change parameters #0 and #2 but leave #1 unchanged, remove the `"param"` object with `id` 1.
+```
+  "params": [
+    {
+      "id": 0,
+      "value": 0.5
+    },
+    {
+      "id": 2,
+      "value": 1.0
+    }
+  ]
+```
+
+Module presets cannot store module patch storage files (introduced in Rack 2).

toc.md

@@ -12,6 +12,7 @@
 - [Plugin Development Tutorial](/PluginDevelopmentTutorial)
 - [Panel Guide](/Panel)
 - [Plugin Manifest](/Manifest)
+- [Module Presets](/Presets)
 - [Voltage Standards](/VoltageStandards)
 - [Digital Signal Processing](/DSP)
 - [Migrating v0.6 Plugins to v1](/Migrate1)