Docs: fix ordering of apt setup (#21192)

docs/sources/installation/debian.md

@@ -37,22 +37,22 @@ Install any missing dependencies:
 sudo apt-get install -y software-properties-common wget
 ```
 
-Add this repository for stable releases:
+Add our GPG key to install signed packages:
 
 ```bash
-sudo add-apt-repository "deb https://packages.grafana.com/oss/deb stable main"
+wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -
 ```
 
-Add this repository if you want beta releases:
+Add this repository for stable releases:
 
 ```bash
-sudo add-apt-repository "deb https://packages.grafana.com/oss/deb beta main"
+sudo add-apt-repository "deb https://packages.grafana.com/oss/deb stable main"
 ```
 
-Add our GPG key to install signed packages:
+Add this repository if you want beta releases:
 
 ```bash
-wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -
+sudo add-apt-repository "deb https://packages.grafana.com/oss/deb beta main"
 ```
 
 Update your APT repositories and install Grafana: