Add privacy policy links to dev edition page

[Bug 1097399](https://bugzilla.mozilla.org/show_bug.cgi?id=1097399)

This is waiting on https://github.com/mozilla/legal-docs/pull/264 before merging, but can be reviewed now. After https://github.com/mozilla/legal-docs/pull/264 is merged, I'll update this PR to pull the latest legal-docs into bedrock.