Countries (RDCR) articles should link to their related Issues articles

[joewiz]

The sidebar of Countries articles such as https://history.state.gov/countries/china should contain a link to any related Issues articles such as https://history.state.gov/countries/issues/china-us-relations.

This was previously in place before the 2016 redesign and appears to have slipped between the cracks of that transition.

See, for example, this screenshot from https://web.archive.org/web/20151017220127/http://history.state.gov/countries/china:

Similarly, the Issues articles should link back to related Countries articles. See, for example, this screenshot from https://web.archive.org/web/20150927121408/http://history.state.gov/countries/issues/german-unification:

Perhaps the fix could be implemented through the in-progress project improving sidebars: #409.