Improve readability of quickstart code

[albusdemens]

Is your feature request related to a problem? Please describe.
People not familiar with SQL might be confused by your code in the "Create a sample database" section in your quickstart page.

Describe the solution you'd like
I would explain that people should make a setup.sql file, and then compile it using sqlite3 ~/test.db < setup.sql. Content of setup.sql:

CREATE TABLE products (
    id INTEGER PRIMARY KEY,
    name TEXT,
    price REAL
);

INSERT INTO products (name, price) VALUES
    ('Widget', 19.99),
    ('Gadget', 29.99),
    ('Gizmo', 39.99),
    ('Smart Watch', 199.99),
    ('Wireless Earbuds', 89.99),
    ('Portable Charger', 24.99),
    ('Bluetooth Speaker', 79.99),
    ('Phone Stand', 15.99),
    ('Laptop Sleeve', 34.99),
    ('Mini Drone', 299.99),
    ('LED Desk Lamp', 45.99),
    ('Keyboard', 129.99),
    ('Mouse Pad', 12.99),
    ('USB Hub', 49.99),
    ('Webcam', 69.99),
    ('Screen Protector', 9.99),
    ('Travel Adapter', 27.99),
    ('Gaming Headset', 159.99),
    ('Fitness Tracker', 119.99),
    ('Portable SSD', 179.99);

[dsp-ant]

This could be a good addition. Do you mind giving this a shot and creating a PR?