Update README to include step by step pages

During Q4 the Modelling Services team have been building the step by step navigation publisher.

README.md

@@ -1,6 +1,12 @@
 # Collections Publisher
 
-The Collections Publisher publishes [/browse pages](https://www.gov.uk/browse/births-deaths-marriages/register-offices) and [/topic pages](https://www.gov.uk/topic/business-enterprise/export-finance). These pages are then served by the [collections app](https://github.com/alphagov/collections).
+The Collections Publisher publishes:
+
+- [/browse pages](https://www.gov.uk/browse/births-deaths-marriages/register-offices)
+- [/topic pages](https://www.gov.uk/topic/business-enterprise/export-finance)
+- [step by step pages](https://www.gov.uk/learn-to-drive-a-car) and [step by step sidebar navigation](https://www.gov.uk/driving-eyesight-rules)
+
+These pages are then served by the [collections app](https://github.com/alphagov/collections).
 
 ![Screenshot of Collections Publisher](docs/screenshot.jpg)
 
@@ -19,19 +25,28 @@ This is a Ruby on Rails application for internal use by GDS and some departmenta
 It has these features:
 
 - Creating & editing topics and mainstream browse pages.
+- Creating & editing step by step navigation pages, and where they are used as sidebar and sticky navigation.
 - Curate the pages tagged to a topic or browse page into "curated lists". This means they'll be displayed in a group with a title. By default, the links are not curated and will appear with a 'A-Z' heading.
 
 ![Screenshot of curated and non-curated pages](docs/screenshot-curated-topics.png)
 
 Left, a [curated mainstream browse page](https://www.gov.uk/browse/childcare-parenting/childcare), right, an [uncurated browse page](https://www.gov.uk/browse/justice/prisons-probation).
 
+![Screenshot of step by step navigation page](docs/screenshot-step-by-step-pages.png)
+
+Example of a [step by step navigation page](https://www.gov.uk/learn-to-drive-a-car).
+
+![Screenshot of step by step navigation sidebar](docs/screenshot-step-by-step-sidebar-navigation.png)
+
+Example of [step by step navigation](https://www.gov.uk/driving-eyesight-rules) used as sidebar navigation for one of the primary pages.
+
 This application uses the [sidekiq](http://sidekiq.org/) message queue for background work (mainly publishing to the Publishing API).
 
 ### Dependencies
 
 - [alphagov/publishing-api](https://github.com/alphagov/publishing-api) -
-  - used for the publishing workflow of `mainstream_browse_page`s, `topic`s and curated lists.
-  - Publishing API sends data onto [Rummager](https://github.com/alphagov/rummager) for search indexing `topic` and `mainstream_browse_page` pages.
+  - used for the publishing workflow of `mainstream_browse_page`s, `topic`s, curated lists and `step_by_step_page`s.
+  - Publishing API sends data onto [Rummager](https://github.com/alphagov/rummager) for search indexing `topic`, `mainstream_browse_page` and `step_by_step_page` pages.
 
 
 ### Running the application