Add support for Next.js >= 13.2

[yoieh]

Fixes #4

ensureApiPage was removed in v13.1.7-canary.14

https://github.com/vercel/next.js/pull/45716/files#diff-2f6fd5a9538abfaf3d5b76a82a8d1ffa029f84a36f0cdae5460520c5cfc2db6bL1402

[brhx]

Excellent spot, thank you! Please could you also update the README.md with the tested version?

[yoieh]

I have updated the Compatibility section of the readme.
This still doesn't give full support for the new app directory with the new Route Handlers.

[brhx]

The typescript type check fails because it needs to be aware of both possible versions of NextNodeServer. I'd like to ensure it doesn't

[yoieh]

I see,
There are more issues here.

ensurePage only exists on the DevServer in version 13.3.0 and not at all NextNodeServer.
This PR will never work in production.

But looks like ensureEdgeFunction exists in both 13.1.6 and 13.3.0 and works in both dev and prod.

[yoieh]

I still kept the ensureApiPage for now..
but it look like you may be able to just use the ensureEdgeFunction from here on.

Not sure when i was added so can not garanti it works with a version lower than 13.1.6.
But this will "make typescript not fail".

[brhx]

Oooh I like this solution! Please could you change it to just ensureEdgeFunction and I will give it a test and merge?