Add v1.8.2 to CHANGELOG.md

(cherry picked from commit fcde2cb)

Author: jrauh01

doc/84-Changelog.md

@@ -1,6 +1,30 @@
 <a id="Changelog"></a>Changelog
 ===============================
 
+v1.8.2
+------
+
+This is a maintenance release that fixes PHP 8.5 deprecation warnings caused by
+using `null` as an array offset, and an incompatibility with IPL HTML in
+`SelectElement::getOption()` calls.
+
+### Upgrading
+
+Packages are available as `icinga-vspheredb`. If you missed the packages
+introduced with v1.8.0, consider switching to them now. For non-package
+installations, please check our [Upgrade Script](01-Installation.md#modul-installation-or-upgrade).
+
+### Fixed issues
+* You can find issues and feature requests related to this release on our
+  [roadmap](https://github.com/Icinga/icingaweb2-module-vspheredb/milestone/21?closed=1)
+
+### PHP Support
+* FIX: No longer using `null` as array offset, which is deprecated in PHP 8.5
+
+### IPL Compatibility
+* FIX: `SelectElement::getOption()` now receives an empty string instead of
+  `null` for the placeholder option (#621)
+
 v1.8.1
 ------