[css-transitions-1][editorial] link to WPT test suite

Author: svgeesus

css-transitions-1/Overview.bs

@@ -33,6 +33,7 @@ Former Editor: David Hyatt, Apple Inc https://www.apple.com/, hyatt@apple.com, w
 Former Editor: Chris Marrin, Apple Inc https://www.apple.com/, cmarrin@apple.com
 Issue Tracking: Bugzilla bugs for this level https://www.w3.org/Bugs/Public/buglist.cgi?query_format=advanced&product=CSS&component=Transitions&resolution=---&status_whiteboard=defer%20to%20level%202&status_whiteboard_type=notregexp
 Issue Tracking: Bugzilla bugs for all levels https://www.w3.org/Bugs/Public/buglist.cgi?query_format=advanced&product=CSS&component=Transitions&resolution=---
+Test Suite: https://wpt.fyi/results/css/css-transitions
 Abstract: CSS Transitions allows property changes in CSS values to occur smoothly over a specified duration.
 Status Text: <strong>This document</strong> is expected to be relatively close to last call.  While some issues raised have yet to be addressed, new features are extremely unlikely to be considered for this level.
 Ignored Vars: x1, x2, y1, y2