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/shell.nix

@@ -0,0 +1,10 @@
+{ pkgs ? import <nixpkgs> {}, ... }:
+
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+    nodejs
+    python3
+    go
+    goimports
+  ];
+}