folder  structure:
- app
___ => pages
___ => components
___ => helpers
___ => services
___ ___ => api
___ ___ ___ => auth.service.ts
___ ___ ___ => product.service.ts
___ ___ ___ => order.service.ts
- theme
___ => form.scss
___ => modal.scss

case standard usage :
-> class = UpperCamelCase
-> function = lowerCamelCase
-> const = lowerCamelCase
-> module = lowerCamelCase
-> local variable = snake_case
-> CSS Class = hyphen-case
-> local state = snake_case
-> localstorage = UpperCamelCase
-> constructor = lowerCamelCase
-> file name = hypen-case
-> url route = hyphen-case

file name : full English