Dawn settings update

[katycobb]

PR Summary:

Our new dense UI makes the online store editor look and feel more like a pro tool, but the settings labels weren't built for this new interface. This is resulting in some too-long text which wraps and makes Dawn's settings look more crowded and tougher to scan than they should be.

This is also an opportunity to bring our settings content up to date based on our newest Polaris content uplift guidelines.

Why are these changes introduced?

Fixes #0.

What approach did you take?

Other considerations

Decision log

#	Decision	Alternatives	Rationale	Downsides
1

Visual impact on existing themes

Testing steps/scenarios

• Step 1

Demo links

• Store
• Editor

Checklist

• Added PR summary for release notes
• Requested review from UX (Only for changes that are affecting the experience or perceivable visual details)
• Created a ticket for the help.shopify.com documentation team about updates to theme settings. (Internal-only task)
• Followed theme code principles
• Linted with Theme Check
• Tested on mobile
• Tested on multiple browsers
• Tested for accessibility

[Roi-Arthur]

Here's a pass purely on settings wording