portico: Change Zulip Standard link on UCSD case study.
portico: Change Zulip Standard link on UCSD case study.

I think it's better for it to point to Standard for Education.

kou/zulip,kou/zulip,hackerkid/zulip,hackerkid/zulip,kou/zulip,rht/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,andersk/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,kou/zulip,andersk/zulip,hackerkid/zulip,eeshangarg/zulip,andersk/zulip,zulip/zulip,kou/zulip,rht/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,rht/zulip,kou/zulip,rht/zulip,hackerkid/zulip,hackerkid/zulip,hackerkid/zulip,kou/zulip,andersk/zulip,zulip/zulip,andersk/zulip,eeshangarg/zulip,zulip/zulip,eeshangarg/zulip,zulip/zulip,hackerkid/zulip,eeshangarg/zulip