Update RG description in release checklist (#3741)

Co-authored-by: Yvonne Fröhlich <94163266+yvonnefroehlich@users.noreply.github.com>

Author: michaelgrund

.github/ISSUE_TEMPLATE/4-release_checklist.md

@@ -47,7 +47,7 @@ assignees: ''
 - [ ] Bump PyGMT version on https://github.com/GenericMappingTools/try-gmt (after conda-forge update)
 - [ ] Announce the release on:
   - [ ] GMT [forum](https://forum.generic-mapping-tools.org/c/news/) (do this announcement first! Requires moderator status)
-  - [ ] [ResearchGate](https://www.researchgate.net) (after forum announcement, add new version as research item via the **code** category, be sure to include the corresponding new Zenodo DOI)
+  - [ ] [ResearchGate](https://www.researchgate.net) (after forum announcement; download the ZIP file of the new release from the [GitHub Releases section](https://github.com/GenericMappingTools/pygmt/releases) and add it as research item via the **code** category, be sure to include the corresponding new Zenodo DOI)
 - [ ] Update release checklist template with any additional bullet points that may have arisen during the release
 
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