Update changelog for #600

CHANGELOG.md

@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - (`lua52`) Support `\z` escape sequences in strings ([#613](https://github.com/JohnnyMorganz/StyLua/issues/613))
   - (`luau`) Support Luau string interpolation ([#607](https://github.com/JohnnyMorganz/StyLua/issues/607))
 - Several optimisations applied to formatting functions to reduce time taken. Files which previously did not terminate (6MB+) now finish in reasonable time. ([#591](https://github.com/JohnnyMorganz/StyLua/issues/591))
+- Assignments of the form `local name = function` will no longer hang at the equals token, and instead force parameters multiline, to reduce unnecessary indentation. ([#595](https://github.com/JohnnyMorganz/StyLua/issues/595))
 
 ### Fixed