chore: add rubocop.yml and update gemspec

rubocop-nexusmods.gemspec

@@ -5,19 +5,16 @@ require_relative "lib/rubocop/nexusmods/version"
 Gem::Specification.new do |spec|
   spec.name = "rubocop-nexusmods"
   spec.version = Rubocop::Nexusmods::VERSION
-  spec.authors = ["Jack Robertson"]
-  spec.email = ["jack.robertson@nexusmods.com"]
+  spec.authors = ["NexusMods Engineering"]
+  spec.email = ["dev@nexusmods.com"]
 
-  spec.summary = "TODO: Write a short summary, because RubyGems requires one."
-  spec.description = "TODO: Write a longer description or delete this line."
-  spec.homepage = "TODO: Put your gem's website or public repo URL here."
+  spec.summary = "NexusMods' style guide for Ruby."
+  spec.description = "Gem containing the rubocop.yml config that corresponds to the NexusMods style guide for Ruby."
+  spec.homepage = "https://gitlab.nexdev.uk/pub/rubocop-nexusmods"
   spec.required_ruby_version = ">= 3.0.0"
 
-  spec.metadata["allowed_push_host"] = "TODO: Set to your gem server 'https://example.com'"
-
-  spec.metadata["homepage_uri"] = spec.homepage
-  spec.metadata["source_code_uri"] = "TODO: Put your gem's public repo URL here."
-  spec.metadata["changelog_uri"] = "TODO: Put your gem's CHANGELOG.md URL here."
+  spec.metadata["allowed_push_host"] = "https://rubygems.org"
+  spec.metadata["source_code_uri"] = spec.homepage
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
@@ -27,13 +24,7 @@ Gem::Specification.new do |spec|
         f.start_with?(*%w[bin/ test/ spec/ features/ .git appveyor Gemfile])
     end
   end
-  spec.bindir = "exe"
-  spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
-  spec.require_paths = ["lib"]
-
-  # Uncomment to register a new dependency of your gem
-  # spec.add_dependency "example-gem", "~> 1.0"
 
-  # For more information and examples about making a new gem, check out our
-  # guide at: https://bundler.io/guides/creating_gem.html
+  spec.add_dependency "rubocop", "~> 1.51"
+  spec.add_dependency "rubocop-shopify", "~> 2.15"
 end

rubocop.yml

+inherit_gem:
+  rubocop-shopify: rubocop.yml
+
+# Organised alphabetically.
+# See https://docs.rubocop.org/rubocop/
+
+Layout/ArgumentAlignment:
+  Enabled: false
+Layout/EmptyLineAfterGuardClause:
+  Enabled: false
+Layout/EmptyLineAfterMagicComment:
+  Enabled: false
+Layout/EmptyLinesAroundAttributeAccessor:
+  Enabled: false
+Layout/EmptyLinesAroundExceptionHandlingKeywords:
+  Enabled: false
+Layout/LeadingCommentSpace:
+  Enabled: false
+Layout/LineEndStringConcatenationIndentation:
+  Enabled: false
+Layout/MultilineOperationIndentation:
+  Enabled: false
+Layout/SpaceInLambdaLiteral:
+  Enabled: false
+
+Naming/InclusiveLanguage:
+  Enabled: false
+
+Security/IoMethods:
+  Enabled: false
+
+Style/CommentAnnotation:
+  Enabled: false
+Style/Documentation:
+  Enabled: false
+Style/GlobalVars:
+  Enabled: false
+Style/GlobalStdStream:
+  Enabled: false
+Style/QuotedSymbols:
+  Enabled: false
+Style/StringLiterals:
+  Enabled: false
+Style/StringLiteralsInInterpolation:
+  Enabled: false
+Style/SymbolArray:
+  Enabled: false
+Style/TrailingCommaInArrayLiteral:
+  Enabled: false
+Style/TrailingCommaInHashLiteral:
+  Enabled: false
+Style/WordArray:
+  Enabled: false