chore(radio): add documentation

PiperOrigin-RevId: 501139954

radio/lib/radio.ts

@@ -23,14 +23,17 @@ import {SingleSelectionController} from './single-selection-controller.js';
 const CHECKED = Symbol('checked');
 
 /**
- * @fires checked
+ * A radio component.
  */
 export class Radio extends LitElement {
   static override shadowRootOptions:
       ShadowRootInit = {...LitElement.shadowRootOptions, delegatesFocus: true};
 
   static formAssociated = true;
 
+  /**
+   * Whether or not the radio is selected.
+   */
   @property({type: Boolean, reflect: true})
   get checked() {
     return this[CHECKED];
@@ -48,6 +51,9 @@ export class Radio extends LitElement {
 
   [CHECKED] = false;
 
+  /**
+   * Whether or not the radio is disabled.
+   */
   @property({type: Boolean, reflect: true}) disabled = false;
 
   /**

radio/radio.ts

@@ -16,7 +16,22 @@ declare global {
   }
 }
 
-/** @soyCompatible */
+/**
+ * @summary Radio buttons allow users to select one option from a set.
+ *
+ * @description
+ * Radio buttons are the recommended way to allow users to make a single
+ * selection from a list of options.
+ *
+ * Only one radio button can be selected at a time.
+ *
+ * Use radio buttons to:
+ * - Select a single option from a set
+ * - Expose all available options
+ *
+ * @final
+ * @suppress {visibility}
+ */
 @customElement('md-radio')
 export class MdRadio extends Radio {
   static override styles = [styles, forcedColorsStyles];