Attempt to support TypeScript for coding challenges

I was a bit weaker than I expected to be in my most recent interview using
TypeScript. To improve, I think I'd like to attempt solving some of the
InterviewCake.com questions using TypeScript.

If you've read the previous commits, the inspiration for `run` arose because I
need to call `npx ts-code <file>`, which is easy enough to remember, but I'd
still rather just call `run <file>`.

deepmind/part_two/reverse-string-in-place.ts

@@ -0,0 +1,6 @@
+function main(x: number) {
+  console.log(x + 1);
+  console.log("Hello, world.");
+}
+
+main(10);