README: add a link to the video showing the example trails

diff --git a/README b/README
index 8fa70b9..b5fba01 100644 (file)
--- a/README
+++ b/README
@@ -53,6 +53,8 @@ frames in the trail, possibly with the most recent frame drawn on top:
 
   $ ./opencv_trail_effect -l 10 -s background -d average -B
 
+Here is a video showing the examples from above:
+https://www.youtube.com/watch?v=X3oRozxt2O4
 
 Side note
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