Anosh D. Ullenius

Replace usage of `strcmp`. If one replaces `strchr` (used in one place) `string.h` can be ditched entirely. PS: I was inspired by your excellent [review of the C standard library](https://nullprogram.com/blog/2023/02/11/)...

Minor refactoring: * Example file is now valid HTML. * Use [strict mode](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode). * Use string literals. * Fix typo.

Thanks for a cool Forth implementation. The JS interoperability makes this very useful. I noticed you'd specified MIT as the licence in the `package.json`-file, but the actual licence file seems...