Layouts: Clean up doc comment for script partial

layouts/partials/resource_builders/script.html

@@ -1,6 +1,20 @@
-{{- $isModule := .module -}}
+{{- /*
+
+Emit an HTML script element referring to a JavaScript resource. The resource can
+be either a path or a Hugo Resource object. If the former, the resource will be
+looked up and built.
+ 
+@context {string|Resource} resource
+  The Resource
+@context {bool} isModule
+  If true, add information to the script element indicating it should be loaded
+  as a module
+
+*/ -}}
 
 {{- $resource := .resource -}}
+{{- $isModule := .module -}}
+
 {{ if $resource.resource }}
   {{ $resource = partial "resource_builders/build_js.html" $resource }}
 {{ end }}