new youtube shortcode with start time

content/topic/improvisation-and-control.md

@@ -7,7 +7,7 @@ has_experiments: ["us-listening-to-machines-listening-to-us.md"]
 
 ## Interactive (music) systems
 
-{{< youtube EZvK8atIlnA >}}
+{{< yt id="EZvK8atIlnA" yt_start="63" modestbranding="true" color="white" >}}
 
 A young, white man is sitting at a white desk. In front of him is a light grey DECstation 5000/200 computer and a black microphone. A simple melody plays. He begins tapping out a rhythm on the desk with his hands. As he modifies his tempo, the system responds. He is improvising. The machine is listening.
 

layouts/shortcodes/yt.html

@@ -0,0 +1,3 @@
+<div {{ with .Get "class" }}class="{{ . }}"{{ else }}style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;"{{ end }}>
+    <iframe src="https://www.youtube.com/embed/{{ .Get "id" }}?enablejsapi=1{{ with .Get "color" }}{{ if eq . "white" }}&color=white{{ end }}{{ end }}{{ with .Get "autoplay" }}{{ if eq . "true" }}&autoplay=1{{ end }}{{ end }}{{ if isset .Params "yt_start" }}&start={{ .Get "yt_start" }}{{ end }}{{ if isset .Params "yt_end" }}&end={{ .Get "yt_end" }}{{ end }}{{ with .Get "modestbranding" }}{{ if eq . "true" }}&modestbranding=1{{ end }}{{ end }}"{{ if .Get "class" }} class="{{ .Get "class" }}"{{ else }} style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" {{ end }} allowfullscreen></iframe>
+</div>