docs(tracing): clarify capture semantics (#11756)

docs/src/api/class-tracing.md

@@ -125,7 +125,9 @@ a timeline preview.
 ### option: Tracing.start.snapshots
 - `snapshots` <[boolean]>
 
-Whether to capture DOM snapshot on every action.
+If this option is true tracing will
+* capture DOM snapshot on every action
+* record network activity
 
 ### option: Tracing.start.sources
 * langs: js, csharp, python

packages/playwright-core/types/types.d.ts

@@ -14708,7 +14708,9 @@ export interface Tracing {
     screenshots?: boolean;
 
     /**
-     * Whether to capture DOM snapshot on every action.
+     * If this option is true tracing will
+     * - capture DOM snapshot on every action
+     * - record network activity
      */
     snapshots?: boolean;