added blurb recommending to check CI workflow for linkcheck warnings

.github/CONTRIBUTING.md

@@ -78,6 +78,8 @@ We recommend installing pandoc using its Anaconda distribution: `conda install -
 
 **NOTE:** it may be expedient at times to avoid running the tutorial notebooks. To do so, add [`nbsphinx_execute = 'never'`](https://nbsphinx.readthedocs.io/en/0.9.3/configuration.html#nbsphinx_execute) to `docs/source/conf.py`. Make sure not to commit these changes!
 
+If you add or change any hyperlinks in the documentation, we recommend checking the "Build documentation" warnings in the GitHub Actions CI workflow to make sure the links will not cause an issue. The CI will not fail due to broken links, only issue a warning (see [issue #286](https://github.com/sandialabs/WecOptTool/issues/286)).
+
 ### Editing the tutorials
 The tutorials are used as part of the Documentation.
 Before pushing any changes make sure that the saved version of the notebooks are clear (no cells run and no results).