Change repository name to gitpod-laravel-starter

[apolopena]

gitpod-laravel8-starter is too specific of a name since this project will now support older versions of Laravel. The repository name should be changed to gitpod-laravel-starter

• Change the name of this repository from gitpod-laravel8-starter to gitpod-laravel-starter
• Remove all hardcoded references to gitpod-laravel8-starter in the entire codebase