fix: clarify part3b backend reference to avoid ambiguity with json-server#4289

Dinokojt7 wants to merge 3 commits into

fullstack-hy2020:sourcefullstack-hy2020/fullstack-hy2020.github.io:sourcefrom

Dinokojt7:fix/part3b-cors-backend-clarificationDinokojt7/fullstack-hy2020.github.io:fix/part3b-cors-backend-clarificationCopy head branch name to clipboard