Chore: use ecmarkup formatter

[justingrant]

From tc39/ecmarkup#536 (comment):

Handling of whitespace is generally managed by the formatter, not the build job, and indeed if you run the formatter on this input it will fix it for you.

As we get closer to Stage 4, it may be helpful to transform our spec text into the standard format used in ECMA-262, so that diffs will be cleaner.

That said, it will create a huge one-time diff when it's run for the first time, so we should pick a time to start formatting when there are no huge PRs pending, in order to reduce any rebase pain for in-progress PRs.

[bakkot]

Re: rebase pain, rebases of this kind can be completely automated, so shouldn't be too bad.

That said, right now Temporal uses multi-line records in source, which ecmarkup doesn't explicitly support, so you may want to hold off on running the formatter until it does (or stop using them, or something).

[ptomato]

If I understand what you mean by "multi-line records" then we already use them inconsistently, so it's probably not too bad to drop them.

[justingrant]

What's a multi-line record?

[bakkot]

Writing a record on multiple lines, like this.

[gibson042]

Related: tc39/ecmarkup#513

[justingrant]

Meeting 2023-08-17: We'll make this change in CI to add the formatter, but only after the big in-flight PRs have been merged.