Add data for Element.animate() options.timeline (#18776)

Checked Firefox, Chromium support, researched Safari, Chromium support.
Mirrors are pure speculation.

Author: ninevra

api/Element.json

@@ -450,6 +450,40 @@
               "deprecated": false
             }
           }
+        },
+        "options_timeline_parameter": {
+          "__compat": {
+            "description": "<code>options.timeline</code> parameter",
+            "spec_url": "https://w3c.github.io/csswg-drafts/web-animations-1/#dom-keyframeanimationoptions-timeline",
+            "support": {
+              "chrome": {
+                "version_added": "85"
+              },
+              "chrome_android": "mirror",
+              "edge": "mirror",
+              "firefox": {
+                "version_added": false
+              },
+              "firefox_android": "mirror",
+              "ie": {
+                "version_added": false
+              },
+              "oculus": "mirror",
+              "opera": "mirror",
+              "opera_android": "mirror",
+              "safari": {
+                "version_added": "16"
+              },
+              "safari_ios": "mirror",
+              "samsunginternet_android": "mirror",
+              "webview_android": "mirror"
+            },
+            "status": {
+              "experimental": false,
+              "standard_track": true,
+              "deprecated": false
+            }
+          }
         }
       },
       "animationcancel_event": {