Created category model and position
edit position model
fix vendor model
fix routes.rb
add migration for rename position's column. Create table to show page
edit show page. Fix table with categories and products.
fix categories and product new form
merge with categories
add new pages for new product and new category
complite new page for products
fix new page for products
Fix models
delete insdex removed file
Edit 'create' function in product controller
fix routes.rb. Also complite new product page
Fix delete product action. Now it is delete entry from Positions table.