Add options for things that don't make sense as extension hooks

Signed-off-by: Jordan Hollinger <[email protected]>

lib/blueprinter/v2.rb

@@ -2,20 +2,29 @@
 
 module Blueprinter
   class V2
+    Options = Struct.new(
+      :exclude_nil,
+      keyword_init: true,
+    )
+
     class << self
-      attr_accessor :views, :fields, :extensions, :blueprint_name
+      attr_accessor :views, :fields, :extensions, :options, :blueprint_name
     end
 
     self.views = {}
     self.fields = {}
     self.extensions = []
+    self.options = Options.new(
+      exclude_nil: false,
+    )
     self.blueprint_name = []
 
     # Initialize subclass
     def self.inherited(subclass)
       subclass.views = { default: subclass }
       subclass.fields = fields.dup
       subclass.extensions = extensions.dup
+      subclass.options = options.dup
       subclass.blueprint_name = subclass.name ? [subclass.name] : blueprint_name.dup
     end