Switch to Goldmark for Google Doc parsing tests.
Switch to Goldmark for Google Doc parsing tests.

Qwiklabs/codelab-tools,Qwiklabs/codelab-tools,googlecodelabs/tools,Qwiklabs/codelab-tools,Qwiklabs/codelab-tools,googlecodelabs/tools,googlecodelabs/tools,googlecodelabs/tools