Update User Welcome intro wording (#63)

[datum-email-designer]

Closes #63

This updates the opening sentence of the User Welcome email so it reads more confidently and is easier to skim.

Before:

Datum is building for a future that is evolving in front of our eyes, so we're shipping updates all the time.

After:

Datum is building for a future that's evolving fast, so we're shipping updates constantly.

The rest of the email is unchanged.

A screenshot of the rendered email will show up as a separate comment on this PR shortly, so you can see exactly how it looks.

Technical details

• Edited the paragraph1 copy string in emails/user-welcome.tsx (first sentence only).
• Ran pnpm generate:all to regenerate config/email-templates/userwelcome-emailtemplate.yaml, which is included in this PR.
• pnpm check (Biome) passes clean.

🤖 Generated with Claude Code

[cla-assistant]

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[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[github-actions]

📧 Template screenshots

Rendered with each template's preview data. Updates automatically as you push.

user-welcome

[scotwells]

Reopening — meant to keep this open as the final, clean canonical example. Sorry for the noise.

[scotwells]

Closing — this PR is a demo of the AI drafting workflow (see issue #63), not meant to be merged. Keeping it around, just closed, as a reference for what a draft looks like.