Mention the fixed regression (#13176)

As best as I learned this was introduced in #11420 and fixed in aabe465
It shouldn't affect almost anyone except for scripting usage of
elixir and (probably most notably) benchee benchmarks that don't
call functions in a module.

CHANGELOG.md

@@ -93,6 +93,7 @@ Finally, we have started enriching our documentation with [Mermaid.js](https://m
 #### Elixir
 
   * [Code] Keep quotes for atom keys in formatter
+  * [Kernel] Re-enabled compiler optimzations for top level functions in scripts (enabled in v1.14.0 but shouldn't impact most programs)
   * [Macro] Address exception on `Macro.to_string/1` for certain ASTs
   * [Module] Make sure file and position information is included in several module warnings (regression)
   * [Path] Lazily evaluate `File.cwd!/0` in `Path.expand/1` and `Path.absname/1`