Fix ADD ADD-ON REPOSITORY TO HA link

This fixes the "ADD ADD-ON REPOSITORY TO HA" link.
From:
`https://my.home-assistant.io/redirect/supervisor_add_addon_repository/?repository_url=https%3A%2F%2Fgithub.com%2FNSPanelManager%2NSPManager`
TO: `https://my.home-assistant.io/redirect/supervisor_add_addon_repository/?repository_url=https%3A%2F%2Fgithub.com%2FNSPManager%2FNSPanelManager`

Author: astritzeqiri

docs/getting-started/install/installation-guide-home-assistant.md

@@ -10,7 +10,7 @@ import CenteredImage from '@site/src/components/CenteredImage';
 
 Thanks to Home Assistant integration, NSPanel manager can be added very easily into your existing Home Assistant server.
 
-[![Open your Home Assistant instance and show the add add-on repository dialog with NSPanelManager pre-filled.](https://my.home-assistant.io/badges/supervisor_add_addon_repository.svg)](https://my.home-assistant.io/redirect/supervisor_add_addon_repository/?repository_url=https%3A%2F%2Fgithub.com%2FNSPanelManager%2NSPManager)
+[![Open your Home Assistant instance and show the add add-on repository dialog with NSPanelManager pre-filled.](https://my.home-assistant.io/badges/supervisor_add_addon_repository.svg)](https://my.home-assistant.io/redirect/supervisor_add_addon_repository/?repository_url=https%3A%2F%2Fgithub.com%2FNSPManager%2FNSPanelManager)
 
 ### Recommended configuration
 
@@ -20,4 +20,4 @@ Check that the add-on should start automatically:
 
 ## After installation is complete
 
-You can now [configure NSPanelManager](./../configuration).
+You can now [configure NSPanelManager](./../configuration).