docs: rpm/deb beta repo.

docs/sources/installation/debian.md

@@ -47,6 +47,12 @@ Create a file `/etc/apt/sources.list.d/grafana.list` and add the following to it
 deb https://packages.grafana.com/oss/deb stable main
 ```
 
+There is a separate repository if you want beta releases.
+
+```bash
+deb https://packages.grafana.com/oss/deb beta main
+```
+
 Use the above line even if you are on Ubuntu or another Debian version. Then add our gpg key. This allows you to install signed packages.
 
 ```bash

docs/sources/installation/rpm.md

@@ -76,6 +76,20 @@ sslverify=1
 sslcacert=/etc/pki/tls/certs/ca-bundle.crt
 ```
 
+There is a separate repository if you want beta releases.
+
+```bash
+[grafana]
+name=grafana
+baseurl=https://packages.grafana.com/oss/rpm-beta
+repo_gpgcheck=1
+enabled=1
+gpgcheck=1
+gpgkey=https://packages.grafana.com/gpg.key
+sslverify=1
+sslcacert=/etc/pki/tls/certs/ca-bundle.crt
+```
+
 Then install Grafana via the `yum` command.
 
 ```bash