Discuss and re-write the non-goals section

[prushforth]

This section reads a little bit insulting, which was not the intent. It was meant to suggest that direct integration of REST APIs is not an achievable of desirable goal of the Web platform.

We should look at some other explainer non-goals sections to see if there is a pattern we should follow.

I would be in favour of removing the section until it can be re-written, fwiw.

[Malvoz]

Here are some non-goals in WICG explainers we can look at:

https://github.com/WICG/portals#objectives
https://github.com/WICG/sanitizer-api#non-goals
https://github.com/WICG/CHIPS#non-goals
https://github.com/WICG/webmonetization/blob/main/docs/explainer.md#non-goals
https://github.com/WICG/contact-api#potential-follow-up-work

and the W3C TAG description of the non-goals section: https://w3ctag.github.io/explainers#non-goals