REFACTOR: global refactoring to be in line with modern JS projects

[doper1]

• More clear code separation
• Refactoring index into two seperate files
• Renaming index as app
• Refactor pok_function into two seperate files

[doper1]

Refactored into a proper API folder structure

[doper1]

Done for now, more refactoring is needed after other issues are settled