Replace "open-source" with "open source"

[ryan-blunden]

Replace all instances of "open-source" in content to "open source" to fix #508

[sqs]

Let's conclude the discussion at #508 before merging this.

[sqs]

• Document this rule in the style guide (open source - no dash #508 (comment))

[ryan-blunden]

@sqs Rule has been added to the specific terms in prose section.

[creachadair]

There's one more to fix at

about/website/src/components/product/OpenSourcePrivacyFeatureItem.tsx

Line 8 in 98708c9

<h4>Open-source, self-managed, &amp; privacy-respectful</h4>

Otherwise, well, I don't love it, but it does what it says on the tin.

[ryan-blunden]

Thanks for the catch @creachadair, I've pushed that change.

[ryan-blunden]

@sqs I'll wait for your approval before merging.