GitHub will prompt you to fork the vf-core repository and then you'll be able to push your branch and open a pull request.
To do this you'll need to have "forked" a file, either with the GitHub web editor, or clone the vf-core repository and make changes locally; here's a helpful video:
Branch naming conventions
In general type/brief-description-of-branch, example: component/advanced-search,
or fix/grid-breaks-on-ios
Here are the most common types:
components/when developing a new component;feature/to be used when working on something that affects the whole system;fix/to be used for ... fixes;hot-fix/something very specific and usually urgent; anddocs/for anything to do with documentation, content or code.
Automated testing
When you push your branch to GitHub, Husky will run a pre-commit hook to help enforce Sass linting and ensure the code builds.
There are also automated test that will run against the GitHub Pull Request.