Add rake rbs

Author: sue445

Rakefile

@@ -9,7 +9,22 @@ require "rubocop/rake_task"
 
 RuboCop::RakeTask.new
 
+namespace :rbs do
+  desc "`rbs collection install` and `git commit`"
+  task :install do
+    sh "rbs collection install"
+    sh "git add rbs_collection.lock.yaml"
+    sh "git commit -m 'rbs collection install' || true"
+  end
+end
+
+desc "Check rbs"
+task :rbs do
+  sh "rbs validate"
+  sh "steep check"
+end
+
 desc "Run all development tasks"
-task dev_all: %i[spec rubocop]
+task dev_all: %i[spec rubocop rbs]
 
 task default: :dev_all