updating footer donate links to add RAND

[najwanan]

Ticket Description: Issue 149

Per doc: The donate feature should support donations to both organizations. [For the RAND link, use https://campaign.rand.org/give/]

Description of Changes

updated footer to include donate link for both RAND and SPEC. Added a link and modified existing link.

Before and After for UI Updates

<-- You should have 2 images minimum, for desktop, 4 for mobile and desktop combined -->

Before:

After:

For PR Reviewer

• [ ] Does this file change the yarn.lock, package.json or package-lock.json file? If so, why?
• [ ] If this pr contains mobile and desktop changes, did you test on IphoneXr and desktop views?
• [ ] Does this file match the related tickets linked figma file, or does it pass the visual smell test?
• [ ] If this file contains javascript, does the javascript pass the smell test?
• [ ] If you don't feel super confident in your review, did you assign someone more senior to double check?