Add prefix route config helper

[markdalgleish]

No description provided.

[changeset-bot]

🦋 Changeset detected

Latest commit: 14dd48c

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

This PR includes changesets to release 10 packages

Name	Type
@react-router/dev	Major
@react-router/fs-routes	Major
@react-router/remix-config-routes-adapter	Major
react-router	Major
react-router-dom	Major
@react-router/architect	Major
@react-router/cloudflare	Major
@react-router/express	Major
@react-router/node	Major
@react-router/serve	Major

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

🤖 Hello there,

We just published version 7.0.0 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 6.28.1-pre.0 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 6.28.1 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 6.28.2-pre.0 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!