Small improvements (#482)

* Update URL

* Add dependabot for actions

Author: wrt54g

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    target-branch: dev

README.md

@@ -25,7 +25,7 @@
 </div>
 
 ## Installation
-1. If you don't have an MQTT broker yet; in Home Assistant go to **Settings → Add-ons → Add-on store** and install the **Mosquitto broker** addon.
+1. If you don't have an MQTT broker yet; in Home Assistant go to **[Settings → Add-ons → Add-on store](https://my.home-assistant.io/redirect/supervisor_store/)** and install the **[Mosquitto broker](https://my.home-assistant.io/redirect/supervisor_addon/?addon=core_mosquitto)** addon.
 1. Go back to the **Add-on store**, click **⋮ → Repositories**, fill in</br>  `https://github.com/zigbee2mqtt/hassio-zigbee2mqtt` and click **Add → Close** or click the **Add repository** button below, click **Add → Close** (You might need to enter the **internal IP address** of your Home Assistant instance first).  
 [![Open your Home Assistant instance and show the add add-on repository dialog with a specific repository URL 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%2Fzigbee2mqtt%2Fhassio-zigbee2mqtt)
 3. The repository includes two add-ons: