Add note about default port used by wrangler dev

[GregBrimble]

Summary

Changes from 8788 to 8787 when migrating from Pages

Documentation checklist

• The documentation style guide has been adhered to.
• If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.
• Files which have changed name or location have been allocated redirects.

[github-actions]

This pull request requires reviews from CODEOWNERS as it changes files that match the following patterns:

Pattern	Owners
/src/content/docs/workers/static-assets	@irvinebroque, @GregBrimble, @WalshyDev, @kodster28, @cloudflare/deploy-config, @cloudflare/pcx-technical-writing

[github-actions]

Preview URL: https://e255fd97.preview.developers.cloudflare.com
Preview Branch URL: https://add-note-about-default-port.preview.developers.cloudflare.com

Files with changes (up to 15)

Original Link	Updated Link
https://developers.cloudflare.com/workers/static-assets/migration-guides/migrate-from-pages/	https://add-note-about-default-port.preview.developers.cloudflare.com/workers/static-assets/migration-guides/migrate-from-pages/