README.md in strava-ruby-client-2.1.0 vs README.md in strava-ruby-client-2.2.0

@@ -12,10 +12,11 @@
 - [Installation](#installation)
 - [Usage](#usage)
   - [Activities](#activities)
     - [Create an Activity](#create-an-activity)
     - [Get Activity](#get-activity)
+    - [List Activity Photos](#list-activity-photos)
     - [List Activity Comments](#list-activity-comments)
     - [List Activity Kudoers](#list-activity-kudoers)
     - [List Activity Laps](#list-activity-laps)
     - [List Athlete Activities](#list-athlete-activities)
     - [Get Activity Zones](#get-activity-zones)
@@ -146,9 +147,34 @@
 
 google_image_url = "https://maps.googleapis.com/maps/api/staticmap?maptype=roadmap&path=enc:#{map.summary_polyline}&key=#{google_maps_api_key}&size=800x800&markers=color:yellow|label:S|#{start_latlng[0]},#{start_latlng[1]}&markers=color:green|label:F|#{end_latlng[0]},#{end_latlng[1]}"
 ```
 
 See [Strava::Models::Map](lib/strava/models/map.rb) for all available properties.
+
+#### List Activity Photos
+
+Returns the photos on the given activity. This API is undocumented in Strava's docs. But there is a discussion in the [strava community hub](https://communityhub.strava.com/t5/developer-discussions/download-all-photos-of-my-own-activities/m-p/11262).
+
+```ruby
+photos = client.activity_photos(1982980795) # => Array[Strava::Models::Photo]
+# in order to request a certain size (by default it will return the biggest size possible):
+# photos = client.activity_photos(1982980795, {size: 1920}) # => Array[Strava::Models::Photo]
+
+photo = photos.first # => Strava::Models::Photo
+
+photo.id # => nil
+photo.unique_id # => '65889142-538D-4EE5-96F5-3DC3B773B1E3'
+photo.urls # => { '0' => 'https://dgtzuqphqg23d.cloudfront.net/eb4DMJ2hJW3k_g9URZEMfaJ8rZfHagrNlZRuEZz0osU-29x64.jpg' }
+photo.athlete_id # => 26_462_176
+photo.activity_id # => 1_946_417_534
+photo.activity_name # => 'TCS NYC Marathon 2018'
+photo.created_at # => Time
+photo.uploaded_at # => Time
+photo.sizes # => { '0' => [29, 64] }
+photo.default_photo # => false
+```
+
+See [Strava::Models::Photo](lib/strava/models/photo.rb) for all available properties.
 
 #### List Activity Comments
 
 Returns the comments on the given activity.