feat(orm): add orm entrypoint with connection and migrator helpers

lib/prism/orm.rb

@@ -0,0 +1,30 @@
+require_relative 'orm/store'
+require_relative 'orm/errors'
+require_relative 'orm/relation'
+require_relative 'orm/validatable'
+require_relative 'orm/associable'
+require_relative 'orm/model'
+require_relative 'orm/migration'
+require_relative 'orm/migrator'
+
+module Prism
+  module Orm
+    class << self
+      def connect(path)
+        @store = Store.new(path)
+      end
+
+      def store
+        @store || raise('Prism::Orm.connect(path) was not called yet')
+      end
+
+      def migrator(migrations_path)
+        Migrator.new(store, migrations_path)
+      end
+
+      def transaction(&block)
+        store.transaction(&block)
+      end
+    end
+  end
+end