fix: Correct Group.angle description

[chavaenc]

This PR

• Updates the Documentation

Describe the changes below:

Fixes #7084 The description incorrectly stated that the method 'Sets' the angle when it
actually adds to it

---

Note

Updates JSDoc for Phaser.GameObjects.Group#angle to state it adds to each member’s angle and adjusts the parameter description accordingly.

^{Written by Cursor Bugbot for commit 8285a78. This will update automatically on new commits. Configure here.}