Tweak options docs to give each a header; draw inspiration from typedoc

[cspotcode]

Our options page:
https://typestrong.org/ts-node/docs/options

Typedoc options page:
https://typedoc.org/guides/options/#configuration-options

I initially tried to keep our options page as terse as possible, using bulleted lists. But now I've come to feel it's less readable: difficult to vertically scan the names, and they don't have headers so don't appear in the sidebar. Headers also make them directly linkable from elsewhere.

Giving each a header, and resigning ourselves to having a taller page, means we can also do the CLI examples like on typedoc's page. Not sure we should do those for options that we would prefer be specified via tsconfig.json.