change project structure

.gitignore

sql/.gitignore

src/.env.example

src/__init__.py

src/items/BookItem.py

src/items/__init__.py

src/middlewares/__init__.py

src/middlewares/middlewares.py

src/pipelines/__init__.py

src/pipelines/pipelines.py

src/scrapy.cfg

src/settings.py

src/spiders/__init__.py

src/spiders/books_spider.py

src/spiders/quotes_spider.py

src/tutorial/alembic.ini

src/tutorial/alembic/README

src/tutorial/alembic/env.py

src/tutorial/alembic/script.py.mako