Add Gemfile and lock for nokogiri since a script now uses it

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

Gemfile

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+
+gem 'nokogiri'

Gemfile.lock

@@ -0,0 +1,17 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    mini_portile2 (2.8.6)
+    nokogiri (1.15.6)
+      mini_portile2 (~> 2.8.2)
+      racc (~> 1.4)
+    racc (1.8.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  nokogiri
+
+BUNDLED WITH
+   2.1.4