Update news and version

Author: 1-Bart-1

NEWS.md

@@ -1,3 +1,14 @@
+## VortexStepMethod v3.3.1 2026-05-13
+
+### Changed
+- `unrefined_deform!` linearly interpolates twist and TE deflection between
+  unrefined sections and rotates each refined section about the average of its
+  adjacent local airfoil normals (#234)
+
+### Fixed
+- `smooth_sqrt` in the solver hot loop keeps gradients defined at zero
+  velocity magnitude
+
 ## VortexStepMethod v3.3.0 2026-05-05
 
 ### Added

Project.toml

@@ -1,7 +1,7 @@
 name = "VortexStepMethod"
 uuid = "ed3cd733-9f0f-46a9-93e0-89b8d4998dd9"
 authors = ["1-Bart-1 <bart@vandelint.net>", "Oriol Cayon and contributors"]
-version = "3.3.0"
+version = "3.3.1"
 
 [workspace]
 projects = ["examples", "examples_cp", "docs", "test"]