Switch to accessibility insights's version of these tools (#603)

* Switch to accessibility insights's version of these tools

* auto-add files meeting strict checks

strict-null-checks/write-tsconfig.js

@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+const fs = require("fs");
+
+module.exports = {
+  writeTsconfigSync: (tsconfigPath, content) => {
+    let serializedContent = JSON.stringify(content, null, "  ");
+    serializedContent += "\n";
+
+    fs.writeFileSync(tsconfigPath, serializedContent);
+  },
+};