docs: add rustdoc comments to all module options

This part of an upcoming effort to generate documentation from code.

Pushing this out before that stage so that the JSON schema is fully documented.

src/modules/custom/label.rs

@@ -10,9 +10,29 @@ use super::{CustomWidget, CustomWidgetContext};
 
 #[derive(Debug, Deserialize, Clone)]
 pub struct LabelWidget {
+    /// Widget name.
+    ///
+    /// **Default**: `null`
     name: Option<String>,
+
+    /// Widget class name.
+    ///
+    /// **Default**: `null`
     class: Option<String>,
+
+    /// Widget text label. Pango markup and embedded scripts are supported.
+    ///
+    /// This is a [Dynamic String](dynamic-values#dynamic-string).
+    ///
+    /// **Required**
     label: String,
+
+    /// Orientation of the label.
+    /// Setting to vertical will rotate text 90 degrees.
+    ///
+    /// **Valid options**: `horizontal`, `vertical`, `h`, `v`
+    /// <br />
+    /// **Default**: `horizontal`
     #[serde(default)]
     orientation: ModuleOrientation,
 }
@@ -24,7 +44,6 @@ impl CustomWidget for LabelWidget {
         let label = build!(self, Self::Widget);
 
         label.set_angle(self.orientation.to_angle());
-
         label.set_use_markup(true);
 
         {