chore(master-issue): improve section descriptions

lib/workers/repository/master-issue.js

@@ -91,7 +91,7 @@ async function ensureMasterIssue(config, branches) {
   if (rateLimited.length) {
     issueBody += '## Rate Limited\n\n';
     issueBody +=
-      'These updates are currently rate limited. Click on a checkbox below to override.\n\n';
+      'These updates are currently rate limited. Click on a checkbox below to force their creation now.\n\n';
     for (const branch of rateLimited) {
       issueBody += getListItem(branch, 'unlimit');
     }
@@ -115,7 +115,7 @@ async function ensureMasterIssue(config, branches) {
   if (awaitingPr.length) {
     issueBody += '## PR Creation Approval Required\n\n';
     issueBody +=
-      "These branches exist but PRs won't be created until you tick the checkbox.\n\n";
+      "These branches exist but PRs won't be created until you approve by ticking the checkbox.\n\n";
     for (const branch of awaitingPr) {
       issueBody += getListItem(branch, 'approvePr');
     }