Correct release file

Author: DRMacIver

hypothesis-python/RELEASE.rst

@@ -3,3 +3,6 @@ RELEASE_TYPE: patch
 This release fixes a small caching bug in Hypothesis internals that may under
 some circumstances have resulted in a less diverse set of test cases being
 generated than was intended.
+
+Fixing this problem revealed some performance problems that could occur during targeted property based testing, so this release also fixes those. Targeted property-based testing should now be significantly faster in some cases,
+but this may be at the cost of reduced effectiveness.