Create examples directory with examples on how to approach specific problems

[fizyk]

• The examples have to be tested on CI
• It'd be enough to run them on a single Python version (highest supported)
• Each example should be in its test file.
• Additional dependencies required for the examples should be added to the 'examples' dependency category in Pipfile

Add examples:

• Examples to use SQLAlchemy with pytest-postgresql
• Examples on using SQLAlchemy and load function (ie to create schema) https://github.com/ClearcodeHQ/pytest-postgresql?tab=readme-ov-file#using-sqlalchemy-to-initialise-basic-database-state