Add a link to the data release policy under "Contribute"

[jahilton]

Why

As a data generator, I would like to understand the policies surrounding the data I am submitting to the DCP

Definition of Done

• a "Data Release Policy" header appears somewhere under https://data.humancellatlas.org/contribute & contains a link to https://drive.google.com/file/d/1kLR0OpEFqS9DdSqFZmM4b2ATFyvwpPum/view

OR

• a "Data Release Policy" header appears somewhere under https://data.humancellatlas.org/contribute & leads to a portal page with the same content as the google doc

[theathorn]

MVP could link to a PDF doc.

[theathorn]

Use same link as suggested in https://app.zenhub.com/workspaces/orange-5d680d7e3eeb5f1bbdf5668f/issues/humancellatlas/data-browser/881

[NoopDog]

Obsolete