fix: json files to use correct author field

[ga-devfront]

Currently the fields are not used in the correct way I update this :

• composer.json requires an authors field while package.json requires an author field.
• I also harmonized everything to provide maximum information :

{
  "name": "PrestaShop SA",
  "email": "[email protected]"
}

• Another small fix is ​​to add an empty line at the end of the file so that it is not picked up by linters, syntax checkers or IDEs.