ADD recommand projects api

app/views/projects/recommend.json.jbuilder

@@ -0,0 +1,22 @@
+json.array! @projects do |project|
+  owner = project.owner
+  json.id project.id
+  json.repo_id project&.repository&.id
+  json.identifier project.identifier
+  json.name project.name
+  json.visits project.visits
+  json.author do
+    json.name owner.try(:show_real_name)
+    json.login owner.login
+    json.image_url url_to_avatar(owner)
+  end
+
+  json.category do
+    if project.project_category.blank?
+      json.nil!
+    else
+      json.id project.project_category.id
+      json.name project.project_category.name
+    end
+  end
+end