Create mobile version of new top nav

### Dependency
- #2686

### Overview
We need to create a mobile version of the new top nav bar so that it can be implemented and launched alongside the desktop version.

### Action Items

- [x] Familiarize yourself with the desktop version of the site’s new top nav bar
- [x] Create a section to the right of the desktop version for the mobile design
- [x] Review the Mobile Navigation Audit in Figma to familiarize yourself with the way mobile nav is designed across the rest of the site
- [x] Create a design that translates the desktop version of this new menu design for mobile.
- [x] Ensure your design is usable and intuitive for mobile, keeps consistent with Design System guidance and other usage across the site, and provides a good experience for users.
- [ ] Once accepted and closed, let development know to make an issue for updating the sitemap, and that they need to put it in the homepage feature branch until homepage launches.

### Resources/Instructions
Figma - [New Top Nav](https://www.figma.com/file/0RRPy1Ph7HafI3qOITg0Mr/Hack-for-LA-Website?node-id=14120%3A92883)
Figma - [Mobile Navigation Audit
](https://www.figma.com/file/0RRPy1Ph7HafI3qOITg0Mr/Hack-for-LA-Website?node-id=15122%3A95165)