feat(hook): add code block hook goat

layouts/_default/_markup/render-codeblock-goat.html

@@ -0,0 +1,16 @@
+{{ $width := .Attributes.width }}
+{{ $height := .Attributes.height }}
+{{ $class := .Attributes.class | default "" }}
+<div class="goat svg-container {{ $class }}">
+    {{ with diagrams.Goat .Inner }}
+        <svg xmlns="http://www.w3.org/2000/svg" font-family="Menlo,Lucida Console,monospace"
+            {{ if or $width $height }}
+                {{ with $width }} width="{{ . }}"{{ end }}
+                {{ with $height }} height="{{ . }}"{{ end }}
+            {{ else }}
+                viewBox="0 0 {{ .Width }} {{ .Height }}"
+            {{ end }}>
+            {{ .Inner }}
+        </svg>
+    {{ end }}
+</div>