New guidelines for external resources presenting GO data

[suzialeksander]

Make a new section explicitly addressing external resources that have GO, like STRING.

This will probably live on the https://geneontology.org/docs/go-citation-policy/ page, and be a section like https://geneontology.org/docs/go-citation-policy#best-practices-for-linking-to-go-entities

[pgaudet]

See also email from Chris 2025-09-12

[suzialeksander]

Draft available at https://geneontology.github.io/docs/guidelines-external/, edits welcome.