add v1.39.2 release note

Author: c9s

doc/release/v1.39.2.md

@@ -0,0 +1,16 @@
+## Fixes
+
+- fixed backtest non-closed kline filtering.
+- fixed margin order sync issue.
+
+## Minor
+
+- added sortino ratio.
+- added strategy config printing support.
+
+[Full Changelog](https://github.com/c9s/bbgo/compare/v1.39.1...main)
+
+ - [#889](https://github.com/c9s/bbgo/pull/889): service/backtest: check and filter kline by its endTime
+ - [#888](https://github.com/c9s/bbgo/pull/888): binance: fix futures/margin order sync issue
+ - [#886](https://github.com/c9s/bbgo/pull/886): Add Sortino ratio
+ - [#881](https://github.com/c9s/bbgo/pull/881): print strategy config