add directions for changes made to website in CONTRIBUTING.md (#3030)
add directions for changes made to website in CONTRIBUTING.md (#3030)

* add directions for changes made to website

* omit run in yarn commands in CONTRIBUTING

* add cd command in contributing

facebook/jest,facebook/jest,bookman25/jest,ide/jest,cpojer/jest,skovhus/jest,mpontus/jest,bookman25/jest,mpontus/jest,bookman25/jest,skovhus/jest,skovhus/jest,ide/jest,ide/jest,facebook/jest,cpojer/jest,mpontus/jest,cpojer/jest