Add view helper props_options

A small shorthand for Props::Options.new. Now we can do

```
json.note props_options
  .partial(“club_notes/notes”, locals: {club_note: @club_note}
  .fragment(“club_note_#{@club_note.id}”)
```

Author: jho406

lib/props_template.rb

@@ -10,6 +10,7 @@
 require "props_template/searcher"
 require "props_template/handler"
 require "props_template/options"
+require "props_template/helper"
 require "props_template/version"
 
 require "active_support"

lib/props_template/helper.rb

@@ -0,0 +1,7 @@
+module Props
+  module Helper
+    def props_options
+      Props::Options.new
+    end
+  end
+end

lib/props_template/railtie.rb

@@ -6,6 +6,7 @@ class Railtie < ::Rails::Railtie
     initializer :props_template do
       ActiveSupport.on_load :action_view do
         ActionView::Template.register_template_handler :props, Props::Handler
+        ActionView::Base.include Props::Helper
         require "props_template/dependency_tracker"
         require "props_template/layout_patch"
         require "props_template/partial_patch"

spec/helper_spec.rb

@@ -0,0 +1,13 @@
+require_relative "support/helper"
+require_relative "support/rails_helper"
+
+RSpec.describe "Props::Helper" do
+  it "returns Props::Options instance" do
+    json = render(<<~PROPS)
+      opts = props_options
+      json.is_a_props_options opts.is_a? Props::Options
+    PROPS
+
+    expect(json).to eql_json({is_a_props_options: true})
+  end
+end

spec/support/rails_helper.rb

@@ -11,6 +11,8 @@
 require "action_dispatch"
 
 class FakeView < ActionView::Base
+  include Props::Helper
+
   # include Rails.application.routes.url_helpers
   # undef_method :fragment_name_with_digest if method_defined? :fragment_name_with_digest
   # undef_method :cache_fragment_name if method_defined? :cache_fragment_name