Update Changelog_6_0.adoc

* CAS: fix for `a && (b || c)`
* Firefox: fix for Algebra View sliders
* API: `ggbApplet.exitFullScreen()` and `ggbApplet.isFullScreenActive()` added
* bugfix: `SetValue(f, ?)` works for functions

reference/modules/ROOT/pages/Changelog_6_0.adoc

@@ -5,7 +5,11 @@ All releases will include the latest minor bugfixes and translation updates.
 *Releases are not simultaneous on all platforms* and not all platforms will get all versions (online and Classic 5 will
 _often_ get an earlier release)
 
-== 6.0.865.0 22nd October 2024 build, not released)
+== 6.0.866.0 24th October 2024 build, not released)
+* CAS: fix for `a && (b || c)`
+* Firefox: fix for Algebra View sliders
+* API: `ggbApplet.exitFullScreen()` and `ggbApplet.isFullScreenActive()` added
+* bugfix: `SetValue(f, ?)` works for functions
 
 == 6.0.864.0 16th October 2024 build)
 * Suite: *Spreadsheet View added*