Try to fix jekyll building error

Author: danifranco

Gemfile

@@ -1,7 +1,4 @@
 source "https://rubygems.org"
 
 # Use the dependency set that GitHub Pages expects:
-gem "github-pages", "~> 232", group: :jekyll_plugins
-
-# For local `bundle exec jekyll serve` on Ruby 3.x:
-gem "webrick", "~> 1.8"
+gem "github-pages", "~> 232", group: :jekyll_plugins

alembic-jekyll-theme.gemspec

@@ -0,0 +1,29 @@
+# coding: utf-8
+
+Gem::Specification.new do |spec|
+  spec.name          = "alembic-jekyll-theme"
+  spec.version       = "4.1.0"
+  spec.authors       = ["David Darnes"]
+  spec.email         = ["me@daviddarnes.com"]
+
+  spec.summary       = %q{A Jekyll boilerplate theme designed to be a starting point for any Jekyll website.}
+  spec.description   = "A Jekyll boilerplate theme designed to be a starting point for any Jekyll website. Rather than starting from scratch, this boilerplate is designed to get the ball rolling immediately."
+  spec.homepage      = "https://alembic.darn.es"
+  spec.license       = "MIT"
+
+  spec.metadata["plugin_type"] = "theme"
+
+  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", "~> 4.1"
+  spec.add_runtime_dependency "jekyll-sitemap", "~> 1.4.0"
+  spec.add_runtime_dependency "jekyll-mentions", "~> 1.6.0"
+  spec.add_runtime_dependency "jekyll-paginate", "~> 1.1.0"
+  spec.add_runtime_dependency "jekyll-seo-tag", "~> 2.7.1"
+  spec.add_runtime_dependency "jekyll-redirect-from", "~> 0.16"
+  spec.add_runtime_dependency "jekyll-feed", "~> 0.15"
+  spec.add_runtime_dependency "jekyll-commonmark", "~> 1.3.1"
+  spec.add_runtime_dependency "jekyll-include-cache", "~> 0.2"
+  spec.add_runtime_dependency "jemoji", "~> 0.12"
+  spec.add_runtime_dependency "jekyll-tabs", "~> 1.2.0"
+end