feat: add manual job box to master issue when in app mode

lib/workers/repository/master-issue.js

@@ -177,6 +177,12 @@ async function ensureMasterIssue(config, branches) {
     issueBody += '\n';
   }
 
+  // istanbul ignore if
+  if (global.appMode) {
+    issueBody +=
+      '---\n<details><summary>Advanced</summary>\n\n- [ ] <!-- manual job -->Check this box to trigger a request for Renovate to run again on this repository\n\n</details>\n';
+  }
+
   if (config.dryRun) {
     logger.info(
       'DRY-RUN: Would ensure Master Issue ' + config.masterIssueTitle