FEATURE: Make artist more creative (#266)

This allows for 2 big features:

1. Artist can ship up to 4 prompts for image generation
2. Artist can regenerate images cause it is aware of seed

This allows for iteration on images maintaining visual style

lib/shared/inference/function.rb

@@ -20,20 +20,26 @@ module ::DiscourseAi
             description: parameter.description,
             required: parameter.required,
             enum: parameter.enum,
+            item_type: parameter.item_type,
           )
         else
           add_parameter_kwargs(**kwargs)
         end
       end
 
-      def add_parameter_kwargs(name:, type:, description:, enum: nil, required: false)
-        @parameters << {
-          name: name,
-          type: type,
-          description: description,
-          enum: enum,
-          required: required,
-        }
+      def add_parameter_kwargs(
+        name:,
+        type:,
+        description:,
+        enum: nil,
+        required: false,
+        item_type: nil
+      )
+        param = { name: name, type: type, description: description, enum: enum, required: required }
+        param[:enum] = enum if enum
+        param[:item_type] = item_type if item_type
+
+        @parameters << param
       end
 
       def to_json(*args)
@@ -47,7 +53,7 @@ module ::DiscourseAi
         parameters.each do |parameter|
           definition = { type: parameter[:type], description: parameter[:description] }
           definition[:enum] = parameter[:enum] if parameter[:enum]
-
+          definition[:items] = { type: parameter[:item_type] } if parameter[:item_type]
           required_params << parameter[:name] if parameter[:required]
           properties[parameter[:name]] = definition
         end