trace-type-specific layout attributes in reference pages (#927)

Author: nicolaskruchten

_includes/plotschema-reference.html

@@ -58,6 +58,21 @@
             {% assign attribute=site.data.plotschema.schema.layout.layoutAttributes %}
             {% assign block = "layout" %}
             {% include reference-block.html parentlink=localparentlink block=block %}
+
+            {% assign localparentlink="layout" %}
+            {% assign attribute=site.data.plotschema.schema.traces.box.layoutAttributes %}
+            {% assign block = "layout" %}
+            {% include reference-block.html parentlink=localparentlink block=block %}
+
+            {% assign localparentlink="layout" %}
+            {% assign attribute=site.data.plotschema.schema.traces.bar.layoutAttributes %}
+            {% assign block = "layout" %}
+            {% include reference-block.html parentlink=localparentlink block=block %}
+
+            {% assign localparentlink="layout" %}
+            {% assign attribute=site.data.plotschema.schema.traces.violin.layoutAttributes %}
+            {% assign block = "layout" %}
+            {% include reference-block.html parentlink=localparentlink block=block %}
     </div>
 </div>