Add date to changelog

Author: pjaap

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## [1.17.0]
+## [1.17.0] - 2026-01-09
 - Add `:symlog` axis scaling for symmetric logarithmic axis scaling, see, e.g. [matplotlib symlog](https://matplotlib.org/stable/gallery/scales/symlog_demo.html)
 - Add `:symlog_threshold` (default = 10.0) to determine when to switch from linear to log scaling in case of `:symlog` scaling