Modernize v2 Docs and Onboarding

[endigo9740]

Linked Issue

Closes #3176

Description

This fixes and updates outdated information and links. See the linked issue for changes.

Changsets

Instructions: Changesets automate our changelog. If you modify files in /packages, run pnpm changeset in the root of the monorepo, follow the prompts, then commit the markdown file. Changes that add features should be minor while chores and bugfixes should be patch. Please prefix the changeset message with feat:, bugfix: or chore:.

Checklist

Please read and apply all contribution requirements.

• This PR targets the dev branch (NEVER master)
• Documentation reflects all relevant changes
• Branch is prefixed with: docs/, feat/, chore/, bugfix/
• Ensure Svelte and Typescript linting is current - run pnpm ci:check
• Ensure Prettier linting is current - run pnpm format
• All test cases are passing - run pnpm test
• Includes a changeset (if relevant; see above)

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
skeleton-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 27, 2025 11:03pm
skeleton-next	❌ Failed (Inspect)			Jan 27, 2025 11:03pm
skeleton-themes	❌ Failed (Inspect)			Jan 27, 2025 11:03pm