Database subcategories table demo-data

[karastoyanov]

We may need to update the demo-data to subcategories table inside the postgres database.

We can start with deleting the old data and inserting new one, more suitable for implementing it into the frond-end from #37.

We can use the script from #21 to introduce the new data, some minor updates may be needed.

[karastoyanov]

• New sub-categories added for Food, Drinks and Accessories, for now we can stick up to three sub-categories.

• New minor updates on the manage_portfolio portfolio script with d6fe7f3