Rename Guide into Preview

Author: nkammah

.github/actions/docs-preview/action.yml

@@ -31,7 +31,7 @@ runs:
           Help us out by validating the Buildkite preview and reporting issues [here](https://github.com/elastic/docs/issues/new?labels=buildkite-migration,bug).
 
             - 📚 HTML diff: [Buildkite](https://${REPO}_bk_${PR}.docs-preview.app.elstc.co/diff)  - [Jenkins](https://${REPO}_${PR}.docs-preview.app.elstc.co/diff)
-            - 📙 Guide: [Buildkite](https://${REPO}_bk_${PR}.docs-preview.app.elstc.co/${GUIDE_CRUMB})  -  [Jenkins](https://${REPO}_${PR}.docs-preview.app.elstc.co/${GUIDE_CRUMB})
+            - 📙 Preview: [Buildkite](https://${REPO}_bk_${PR}.docs-preview.app.elstc.co/${GUIDE_CRUMB})  -  [Jenkins](https://${REPO}_${PR}.docs-preview.app.elstc.co/${GUIDE_CRUMB})
             - 🧪 [Buildkite vs Jenkins diff](https://github.com/elastic/built-docs/compare/${REPO}_bk_${PR}..${REPO}_${PR})`;
 
           github.rest.issues.createComment({