Update "More at Stanford" links on main exhibits page to coincide with new library website launch

[caaster]

(Updated by Sarah: Can be completed with other url updates rolling out Monday, July 31st.)

Change the links under the More at Stanford dropdown on https://exhibits.stanford.edu/ so that they go to the correct pages on the new library website or other location (SW) as indicated.

• Other library collections at Stanford - change existing link text (https://library.stanford.edu/collections) to: Explore library collections at Stanford - new link: https://library.stanford.edu/explore-collections
• Special Collections & University Archives (current link: https://library.stanford.edu/spc) - new link: https://library-prod.stanford.edu/libraries/special-collections
• Giving to Stanford Libraries - change existing link text (https://library.stanford.edu/department/library-communications-and-development) to: Support the Stanford Libraries - new link: https://library.stanford.edu/support-stanford-libraries

[saseestone]

Related to: sul-dlss/SearchWorks#3344, sul-dlss/mylibrary#891, sul-dlss/SearchWorks#3346