Add user documentation about the new avatar trait.

docs/USER_GUIDE.adoc

@@ -81,6 +81,25 @@ project is created for each repository.
 +
 image::images/screenshot-9.png[scaledwidth=90%]
 
+[id=bitbucket-avatar]
+== Avatar
+
+This plugin have customized icon designed for the "Organization Folder" image:/src/main/webapp/images/bitbucket-logo.svg[icon,20,20], for "Multibranch Pipeline", for Single Repository image:/src/main/webapp/images/bitbucket-repository-git.svg[icon,20,20] and Folder image:/src/main/webapp/images/bitbucket-scmnavigator.svg[icon,20,20] project type. This is the default behaviour of the plugin starting from version 935.
+It is possible associate the Bitbucket avatar to the project item selecting the "Show Bitbucket avatar images" behaviour in the project configuration.
++
+image::images/screenshot-19.png[scaledwidth=90%]
+
+The supported avatars are:
+
+* Organization Folder:
+** Cloud: workspace avatar
+** Data Center: project avatar
+* Multibranch Repository:
+** Cloud: repository avatar
+** Data Center: does not support customization of the repository avatar
+
+The default Bitbucket avatar is a generated SVG image, since this plugin does not support SVG format, this image will be replaced by a Jenkins random generated image.
+
 [id=bitbucket-webhooks]
 == Webhooks registering
 
@@ -105,7 +124,7 @@ image::images/screenshot-14.png[scaledwidth=90%]
 For both Bitbucket _Multibranch Pipelines_ and _Organization folders_ there is an "Override hook management" behavior
 to opt out or adjust system-wide settings.
 
-image::images/screenshot-4.png[scaledwidth=90%]
+image::images/screenshot-18.png[scaledwidth=90%]
 
 IMPORTANT: In order to have the auto-registering process working fine the Jenkins base URL must be
 properly configured in _Manage Jenkins_ » _System_

src/main/java/com/cloudbees/jenkins/plugins/bitbucket/server/client/repository/BitbucketServerProject.java

@@ -38,8 +38,6 @@
     @JsonProperty("name")
     private String displayName;
 
-    private String avatar;
-
     @JsonProperty("links")
     @JsonDeserialize(keyAs = String.class, contentUsing = BitbucketHref.Deserializer.class)
     private Map<String,List<BitbucketHref>> links;
@@ -61,6 +59,6 @@
 
     @Override
     public String getAvatar() {
-        return avatar == null ? getLink("self") + "/avatar.png" : avatar;
+        return getLink("self") + "/avatar.png";
     }
 }