extract mtimes of Pages and Documents to API

Author: ashmaroli

lib/jekyll-admin/apiable.rb

@@ -47,6 +47,10 @@ def to_api(include_content: false)
         output["name"] = basename
       end
 
+      if is_a?(Jekyll::Page) || is_a?(Jekyll::Document)
+        output["modified_at"] = mtime
+      end
+
       output
     end
 
@@ -70,6 +74,10 @@ def name
       @name
     end
 
+    def mtime
+      @mtime ||= File.stat(file_path).mtime
+    end
+
     def file_contents
       @file_contents ||= File.read(file_path, file_read_options) if file_exists?
     end