Make sure to include service worker and manifest in theme gem

Author: daviddarnes

alembic-jekyll-theme.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
 
   spec.metadata["plugin_type"] = "theme"
 
-  spec.files         = `git ls-files -z`.split("\x0").select { |f| f.match(%r{^(assets|_layouts|_includes|_sass|LICENSE|README)}i) }
+  spec.files         = `git ls-files -z`.split("\x0").select { |f| f.match(%r{^(assets|_layouts|_includes|_sass|LICENSE|README|sw|manifest)}i) }
 
   spec.add_runtime_dependency "jekyll", "~> 3.6"
   spec.add_runtime_dependency "jekyll-sitemap", "~> 0.13"