Rendering of strings doesn't match toml-rs

[epage]

While we intentionally chose to prefer " over ' when no escaping is needed (because this is most likely what users will do), we should probably use """ to avoid quoting " in strings.

We also need to look into our \t handling.

Compare

• toml-rs pretty_tricky
• Our pretty_tricky added in https://github.com/ordian/toml_edit/pull/286

Note: This only impacts content we auto-generate formatting for. We still preserve a users formatting when roundtripping through the format-preserving API.