chore: Update version matrix

Author: lorenzulrich

README.md

@@ -4,8 +4,9 @@
 
 This package is currently maintained for the following versions:
 
-| TYPO3 Version         | Package Version | Branch  | Maintained    |
-|-----------------------|-----------------|---------|---------------|
-| TYPO3 11.5.x          | 3.x             | master  | Yes           |
-| TYPO3 8.7.x           | 2.x             | -       | No            |
-| TYPO3 6.2.x           | 1.x             | -       | No            |
+| TYPO3 Version | Package Version      | Branch | Maintained |
+|---------------|----------------------|--------|------------|
+| TYPO3 13.4.x  | 4.x (in development) | master | Yes        |
+| TYPO3 11.5.x  | 3.x                  | v3     | No         |
+| TYPO3 8.7.x   | 2.x                  | -      | No         |
+| TYPO3 6.2.x   | 1.x                  | -      | No         |