Update require for breaking change in commander@12.0.0.

markdownlint.js

@@ -7,7 +7,7 @@ const path = require('node:path');
 const Module = require('node:module');
 const os = require('node:os');
 const process = require('node:process');
-const program = require('commander');
+const {program} = require('commander');
 const glob = require('glob');
 const markdownlint = require('markdownlint');
 const rc = require('run-con');