chore: support custom filename in screenshot function (#349)

README.md

@@ -341,6 +341,7 @@ X Y coordinate space, based on the provided screenshot.
   - Description: Take a screenshot of the current page. You can't perform actions based on the screenshot, use browser_snapshot for actions.
   - Parameters:
     - `raw` (boolean, optional): Whether to return without compression (in PNG format). Default is false, which returns a JPEG image.
+    - `filename` (string, optional): File name to save the screenshot to. Defaults to `page-{timestamp}.{png|jpeg}` if not specified.
     - `element` (string, optional): Human-readable element description used to obtain permission to screenshot the element. If not provided, the screenshot will be taken of viewport. If element is provided, ref must be provided too.
     - `ref` (string, optional): Exact target element reference from the page snapshot. If not provided, the screenshot will be taken of viewport. If ref is provided, element must be provided too.
   - Read-only: **true**
@@ -501,7 +502,8 @@ X Y coordinate space, based on the provided screenshot.
 - **browser_pdf_save**
   - Title: Save as PDF
   - Description: Save page as PDF
-  - Parameters: None
+  - Parameters:
+    - `filename` (string, optional): File name to save the pdf to. Defaults to `page-{timestamp}.pdf` if not specified.
   - Read-only: **true**
 
 ### Utilities