feat: Add support for custom remote javascript files (#751)

### Prerequisites

Put an `x` into the box(es) that apply:

- [ ] This pull request fixes a bug.
- [X] This pull request adds a feature - #750 
- [ ] This pull request introduces breaking change.

### Description

Add a new configuration item and use resources.GetRemote to gather the
remote asset.

### Checklist

#### General

- [X] Describe what changes are being made
- [X] Explain why and how the changes were necessary and implemented
respectively

#### Resources

- [X] If you have changed any SCSS code, run `make release` to
regenerate all CSS files

#### Contributors

- [X] Add yourself to `CONTRIBUTORS.md` if you aren't on it already