Add mushroom shadow theme (#39)

* Add mushroom shadow theme

* Improve readme

README.md

@@ -2,24 +2,27 @@
 
 [![hacs][hacs-badge]][hacs-url]
 
-**🚨 Mushroom theme is not needed anymore if you have Home Assistant 2022.11 `version`!
-If you use Mushroom Square theme, you can keep it, otherwise, you can uninstall it.**
-
-Mushroom themes allow you to customize your Mushroom dashboard using [Home Assistant][home-assistant] themes.
+> **Warning** Mushroom theme is not needed anymore if you have Home Assistant 2022.11 `version`!
+> You only need it if you want `Square` or `Shadow` theme.
 
 > **Warning**
 > It's only a theme! You need to install [Mushroom][mushroom] if you want to use Mushroom cards!
 
+## Description
+
+Mushroom themes allow you to customize your Mushroom dashboard using [Home Assistant][home-assistant] themes.
+
 ![Overview](https://user-images.githubusercontent.com/5878303/152695688-9d705231-500c-49e7-82f5-69e206da95db.png)
 
 ## Usage
 
 Just select your theme in your Home Assistant profile settings.
 
-2 themes are available :
+3 themes are available :
 
--   Mushroom (default)
--   Mushroom square
+-   Mushroom (default) : If you use this one, just simply uninstall Mushroom Themes as it's now part of Home Assistant default theme.
+-   Mushroom Square
+-   Mushroom Shadow
 
 ## Build your own
 

themes/mushroom-shadow.yaml

@@ -0,0 +1,6 @@
+Mushroom Shadow:
+    ha-card-box-shadow: 0px 2px 4px 0px rgba(0,0,0,0.16)
+    ha-card-border-width: 0
+    modes:
+        light: {}
+        dark: {}