feat: Update README.md

[maximkrouk]

Added a guide on bypassing swift-syntax version resolution

Note

Some of my dependencies prevent me from using latest version of swift-macro-toolkit, but by depending on local swift-syntax fork I managed to bypass swift-syntax version resolution. It's too small piece of knowledge to make some article about, but I think some folks may find it really helpful and swift-macro-toolkit looks like a right place to mention it.

[stackotter]

Are you saying that if your app depends on a local swift-syntax checkout, SwiftPM then uses that swift-syntax checkout for swift-macro-toolkit as well?

[maximkrouk]

Nope, for example:

• swift-composable-architecture depends on swift-syntax ..<603
• swift-associated-objects depends on swift-macro-toolkit 0.6.0..<0.9.0
• swift-macro-toolkit is a transitive dependency in my app

Afair standard resolution checked out swift-macro-toolkit at 0.7.x. It couldn't use 0.8.0 because TCA (and some of it's deps) limited swift-syntax to 602

I simply cloned swift-syntax to a local directory and added a local dependency to app's Package.swift, since swift-syntax version was resolved as a local clone, it's no longer limiting swift-macro-toolkit

Sure it may not always work, but at least worked with 603 and likely to work in most cases as long as swift version matches (6xy/7xy etc)