Add new plugin files.

This gets the plugin running again without name collisions. A solid starting point

lib/discourse_donations/engine.rb

@@ -1,8 +0,0 @@
-# frozen_string_literal: true
-
-module ::DiscourseDonations
-  class Engine < ::Rails::Engine
-    engine_name 'discourse-donations'
-    isolate_namespace DiscourseDonations
-  end
-end

lib/discourse_patrons/engine.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+module ::DiscoursePatrons
+  PLUGIN_NAME = "discourse-patrons"
+
+  class Engine < ::Rails::Engine
+    engine_name DiscoursePatrons::PLUGIN_NAME
+    isolate_namespace DiscoursePatrons
+  end
+end