Link diagnostics to TSWhy #1692

https://github.com/kitsonk/tswhy

Their plan is to define shortcodes for TS diagnostics, eventually get those shortcodes into the TS compiler, and also to create a website that explains each diagnostic code in depth.

Tools like TS, deno, and ts-node can link directly to this website from CLI output, using ANSI hyperlink codes.