Troubleshooting docs still say turbopack is unsupported despite v1.15.0 adding support

[DBosley]

Problem

The troubleshooting page still states:

You are probably using a turbopack enabled build (next build --turbo) which is not currently supported by OpenNext.

However, v1.15.0 (released Jan 21, 2025) added turbopack runtime detection ("fix: use the correct runtime (i.e. webpack or turbopack)") and Next 16 support (which uses turbopack by default).

This was originally tracked in opennextjs/opennextjs-cloudflare#569.

Suggested Fix

Update the troubleshooting section to reflect that turbopack builds are supported as of v1.15.0, and remove or qualify the blanket "not currently supported" statement.

[vicb]

@DBosley would you mind sending a PR on this doc repo to fix that?