docs(ui,window): update comments related to metrics handling

Adjust comments to better reflect metrics-related behavior; no functional changes.

src/ui/window.c

@@ -750,8 +750,9 @@ win_page_down(ProfWin* window, int scroll_size)
         win_update_virtual(window);
     }
 
-    /*switch off page if no messages left to read
-    TODO: update buffer end handling to check  meassages just after last entry*/ 
+    /* Switch off page if no messages left to read.
+     * TODO: update buffer end handling to check messages just after last entry.
+     */
     if (*scroll_state == WIN_SCROLL_REACHED_BOTTOM) {
         window->layout->paged = 0;
         window->layout->unread_msg = 0;