[BML-5] Add samples folder with sample dataset

[BorodaUA]

Hi 👋 team, please review changes that I made in scope of following task(s):

• [BML-5] Add samples folder with sample dataset

Here what is done:

• Added samples folder with dataset with bills from wiki page https://github.com/dreamproit/BillML/wiki/Customized-model:-trained-with-the-%22Salesforce-query-focused-sum%22-model