Consolidate howto/website-guidelines-checklist and the original guidelines?

The [website-guidelines-checklist.md] file is very useful indeed, but I'm thinking that it would be even better if the [original guide](https://github.com/cncf/foundation/blob/master/website-guidelines.md) was written in a check-list format. That way we can avoid having these documents drift.

WDYT?

[website-guidelines-checklist.md]: https://github.com/cncf/techdocs/blob/main/howto/website-guidelines-checklist.md