Add rebuild instructions

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

@@ -33,7 +33,23 @@ runs:
             - 🔨 Buildkite [builds](https://buildkite.com/elastic/docs-build-pr/builds?meta_data[repo_pr]=${REPO}_${PR})
             - 📚 HTML diff: [Buildkite](https://${REPO}_bk_${PR}.docs-preview.app.elstc.co/diff)  - [Jenkins](https://${REPO}_${PR}.docs-preview.app.elstc.co/diff)
             - 📙 Preview: [Buildkite](https://${REPO}_bk_${PR}.docs-preview.app.elstc.co/${PREVIEW_PATH})  -  [Jenkins](https://${REPO}_${PR}.docs-preview.app.elstc.co/${PREVIEW_PATH})
-            - 🧪 [Buildkite vs Jenkins diff](https://github.com/elastic/built-docs/compare/${REPO}_bk_${PR}..${REPO}_${PR})`;
+            - 🧪 [Buildkite vs Jenkins diff](https://github.com/elastic/built-docs/compare/${REPO}_bk_${PR}..${REPO}_${PR})
+
+           <details>
+            <summary>Triggering rebuilds</summary>
+        You can manually trigger a new Buildkite build with any of the below commands:
+          \`\`\`
+run docs-build
+run docs-build rebuild
+run docs-build warnlinkcheck
+run docs-build skiplinkcheck (takes precedence over the warnlinkcheck option)
+buildkite test this
+buildkite test this rebuild
+buildkite test this warnlinkcheck
+buildkite test this skiplinkcheck 
+          \`\`\`
+          </details>
+          `;
 
           github.rest.issues.createComment({
             issue_number: PR,