chore: bump docs links (#86)

Co-authored-by: danthorpe <danthorpe@users.noreply.github.com>

Author: danthorpe

README.md

@@ -10,7 +10,7 @@ Swift Networking, or `swift-networking`, is a library for building a flexible ne
 
 ## 📚 Documentation
 
-Browse the documentation for [main](https://danthorpe.github.io/swift-networking/main/documentation/networking/), [0.3.0](https://danthorpe.github.io/swift-networking/0.3.0/documentation/networking/).
+Browse the documentation for [main](https://danthorpe.github.io/swift-networking/main/documentation/networking/), [0.4.0](https://danthorpe.github.io/swift-networking/0.4.0/documentation/networking/).
 
 ## 🤔 What is Swift Networking?
 Swift Networking is a Swift Package, which provides some core tools used to make HTTP network requests.