Add HACS installation in README

Author: relvacode

README.md

@@ -5,6 +5,12 @@ Transform your Home Assistant smart bulbs into a media player
 When an image is played on a LightCast media player, it uses [colorgram.py](https://github.com/obskyr/colorgram.py/tree/master) 
 to extract a palette of colors equal to the amount of lights configured in the LightCast player and sets those lights to that color palette.
 
+## Installation
+
+This integration is compatible with HACS
+
+Add a [custom repository](https://hacs.xyz/docs/faq/custom_repositories/) pointing to `relvacode/LightCast` and install
+
 ## Configuration
 
 `configuration.yml`