Minimize files included in the distributed Gem

Author: simukappu

README.md

@@ -325,6 +325,8 @@ See [Testing](/docs/Testing.md#Testing).
 
 ## Documentation
 
+`docs/` contains documentation for users to read. These files are included in the distributed Gem. `ai-docs/` contains AI-generated and design documents. These files are not included in the distributed Gem.
+
 See [API Reference](http://www.rubydoc.info/github/simukappu/activity_notification/index) for more details.
 
 RubyDoc.info does not support parsing methods in *included* and *class_methods* of *ActiveSupport::Concern* currently.

activity_notification.gemspec

@@ -15,8 +15,7 @@ Gem::Specification.new do |s|
   s.description   = "Integrated user activity notifications for Ruby on Rails. Provides functions to configure multiple notification targets and make activity notifications with notifiable models, like adding comments, responding etc."
   s.license       = "MIT"
 
-  s.files         = `git ls-files`.split("\n")
-  s.test_files    = `git ls-files -- spec/*`.split("\n")
+  s.files         = Dir.glob("lib/**/*") + Dir.glob("app/**/*") + Dir.glob("docs/**/*") + ["README.md", "MIT-LICENSE"]
   s.require_paths = ["lib"]
   s.required_ruby_version = '>= 2.1.0'