Introduced a new environment variable, MAMC_SECRET, to securely fetch champion data from an external API. This secret is now used in the ChampionSeeder, ChampionSkinSeeder and SkinChromaSeeder classes to authenticate requests. The .env.example and app configuration files have been updated accordingly.
- Moved the import statement for `Champion` and `ChampionSkin` models in their respective controllers to improve code organization.
- Refactored image attribute methods in the `Champion` model to use string interpolation for better readability.
- Refactored image attribute methods in the `ChampionSkin` model to use string interpolation for better readability.
This commit improves code organization and readability by refactoring import statements and using string interpolation for image attribute methods.
