Use astronaut design for startup screen

[marvinhagemeister]

This PR adds a redesigned startup screen. It tries to fit with the logo we'll share soon.

Before:

After:

[changeset-bot]

🦋 Changeset detected

Latest commit: 78eb213

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
wmr	Patch

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[github-actions]

Size Change: +152 B (0%)

Total Size: 692 kB

Filename	Size	Change
packages/wmr/wmr.cjs	659 kB	+152 B (0%)

ℹ️ View Unchanged

Filename	Size	Change
examples/demo/dist/about/index.html	657 B	0 B
examples/demo/dist/assets/Calendar.********.css	702 B	0 B
examples/demo/dist/assets/style.********.css	386 B	0 B
examples/demo/dist/chunks/class-fields.********.js	201 B	0 B
examples/demo/dist/chunks/compat.********.js	15.3 kB	0 B
examples/demo/dist/chunks/index.********.js	200 B	0 B
examples/demo/dist/chunks/prerender.********.js	2.44 kB	0 B
examples/demo/dist/class-fields/index.html	635 B	0 B
examples/demo/dist/compat/index.html	1.49 kB	0 B
examples/demo/dist/env/index.html	712 B	0 B
examples/demo/dist/error/index.html	646 B	0 B
examples/demo/dist/files/index.html	675 B	0 B
examples/demo/dist/index.********.js	7.19 kB	0 B
examples/demo/dist/index.html	703 B	0 B
examples/demo/dist/lazy-and-late/index.html	658 B	0 B

_{compressed-size-action}

[developit]

LGTM! A couple of styling things I'd prefer, lmk.