Closes #12107: Document support for plugin-provided dashboard widgets

docs/plugins/development/dashboard-widgets.md

@@ -0,0 +1,52 @@
+# Dashboard Widgets
+
+!!! note "Introduced in v3.5"
+    Support for custom dashboard widgets was introduced in NetBox v3.5.
+
+Each NetBox user can customize his or her personal dashboard by adding and removing widgets and by manipulating the size and position of each. Plugins can register their own dashboard widgets to complement those already available natively.
+
+## The DashboardWidget Class
+
+All dashboard widgets must inherit from NetBox's `DashboardWidget` base class. Subclasses must provide a `render()` method, and may override the base class' default characteristics.
+
+Widgets which require configuration by a user must also include a `ConfigForm` child class. This form is used to render the user configuration options for the widget.
+
+::: extras.dashboard.widgets.DashboardWidget
+
+## Widget Registration
+
+To register a dashboard widget for use in NetBox, import the `register_widget()` decorator and use it to wrap each `DashboardWidget` subclass:
+
+```python
+from extras.dashboard.widgets import DashboardWidget, register_widget
+
+@register_widget
+class MyWidget1(DashboardWidget):
+    ...
+
+@register_widget
+class MyWidget2(DashboardWidget):
+    ...
+```
+
+## Example
+
+```python
+from django import forms
+from extras.dashboard.utils import register_widget
+from extras.dashboard.widgets import DashboardWidget
+
+
+@register_widget
+class ReminderWidget(DashboardWidget):
+    default_title = 'Reminder'
+    description = 'Add a virtual sticky note'
+
+    class ConfigForm(forms.Form):
+        content = forms.CharField(
+            widget=forms.Textarea()
+        )
+
+    def render(self, request):
+        return self.config.get('content')
+```