docs: for PR #4120

ACKNOWLEDGEMENTS.md

@@ -1160,3 +1160,4 @@ Further device support has been made with the assistance of users. Please consid
 - [lethargus](https://github.com/lethargus) for assisting with support for Lumary B2 ceiling fan with RGB+CW light.
 - [MIKOLAJW197](https://github.com/MIKOLAJW197) for contributing improvements to the vacuum entity.
 - [barijaona](https://github.com/barijaona) for contributing support for SRNE SE Series lithium battery.
+- [marcins](https://github.com/marcins) for contributing support for Henden Essential pool heat pump.

DEVICES.md

@@ -149,6 +149,7 @@
 - Evotherm ETI series heat pump
 - Fairland IPHCR15, RMIC06, X20 pool heat pumps (also Pool Systems and other brands)
 - Garden PAC pool heat pump (also works with Summerwave Si Series)
+- Henden Essential pool heat pump
 - Komeco QC60 pool heat pump
 - Madimack Eco, Elite V2,V3,V4 and other model pool heat pumps
 - Poolex Silverline, Q-7, Q-line, Arctic, Vertigo, Ice Spa, Mag FI heat pumps