I would recommend NOT using AngularJS any longer as v13 is the latest Umbraco version that uses AngularJS and starting from v14, the new Umbraco backoffice has stopped using AngularJS and it has replaced the deprecated AngularJS code with Lit and TypeScript, so things are very different in v14 and higher and all your changes will be useless next time you upgrade your project to a higher version of Umbraco.

Umbraco recommends following this following Umbraco documentation for creating packages: https://docs.umbraco.com/umbraco-cms/extending/packages/creating-a-package

You can also follow the same document to create NuGet packages: https://docs.umbraco.com/umbraco-cms/extending/packages/creating-a-package#creating-a-nuget-package