add license file and section in the readme file

Merge pull request #1 from Rhaegar121/feature

update readme file

update readme file

add request tests for controllers in spec/request

add validation tests for models in spec/models

add test for scraper method in scraper_spec.rb

use webmock to stub requests in rails_helper.rb

install rspec gem and setup rspec

bypass cors policy with cors gem by giving temporary access

add show method in categories_controller to retrieve scraped data

install sidekiq and sidekiq-cron for background jobs

add scraped_at (timestamp) column to products table

save the scraped data in the database

scrape the page