Centralize Font Files in Monorepo for React and React Native Storybook Integration

### **Description**

Centralize MetaMask design system font files within the monorepo to be accessible by both React and React Native Storybook environments. This will serve as the official repository for downloading font files for all MetaMask projects.

### **Technical Details**

- Create a directory within the monorepo dedicated to design system assets, including fonts.
- Upload the required font files into this directory.
- Update React Storybook to reference the centralized font directory.
- Update React Native Storybook to utilize the same centralized font directory, ensuring compatibility across platforms.
- Add documentation on how to access and use these fonts for developers working on MetaMask projects.
- Consider implementing a script or workflow to manage and update the fonts when necessary.

### **Acceptance Criteria**

- Font files are hosted in a single, centralized location within the monorepo.
- React and React Native Storybooks are able to access and display fonts from this location.
- Documentation is updated to include the location and usage of these font files for MetaMask developers.
- Ensure cross-platform compatibility for the fonts.
- Verify that the design system assets align with project-wide standards.

No files, tests, or entry points are named. Start by locating the React and React Native Storybook font configuration and the monorepo's existing design-system asset structure. Done means both Storybooks load the centralized fonts, the fonts are cross-platform compatible, and developer documentation explains their location and use.

Written by the indexing model from the issue text.