#3341 doc: add Debian 13 installation instructions

Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>

Author: pbek

CHANGELOG.md

@@ -1,5 +1,11 @@
 # QOwnNotes Changelog
 
+## 25.8.4
+
+- There now is a software repository for **Debian Linux 13.0**
+  - Please visit the [Debian installation page](https://www.qownnotes.org/installation/debian.html)
+    for instructions (for [#3341](https://github.com/pbek/QOwnNotes/issues/3341))
+
 ## 25.8.3
 
 - Added a **new editor color schema** _Shark - Origami_ by @Inventhrice

webpage/src/installation/debian.md

@@ -27,6 +27,33 @@ This package is built with Qt6.
 
 [Direct Download](https://download.opensuse.org/repositories/home:/pbek:/QOwnNotes/Debian_Unstable)
 
+## Debian 13.0
+
+Run the following shell commands to trust the repository.
+
+```bash
+SIGNED_BY='/etc/apt/keyrings/qownnotes.gpg'
+sudo mkdir -p "$(dirname "${SIGNED_BY}")"
+curl --silent --show-error --location http://download.opensuse.org/repositories/home:/pbek:/QOwnNotes/Debian_13/Release.key | gpg --dearmor | sudo tee "${SIGNED_BY}" > /dev/null
+sudo chmod u=rw,go=r "${SIGNED_BY}"
+```
+
+Run the following shell commands to add the repository and install QOwnNotes from there.
+
+```bash
+SIGNED_BY='/etc/apt/keyrings/qownnotes.gpg'
+ARCHITECTURE="$(dpkg --print-architecture)"
+echo "deb [arch=${ARCHITECTURE} signed-by=${SIGNED_BY}] http://download.opensuse.org/repositories/home:/pbek:/QOwnNotes/Debian_13/ /" | sudo tee /etc/apt/sources.list.d/qownnotes.list > /dev/null
+sudo apt update
+sudo apt install qownnotes
+```
+
+::: tip
+This package is built with Qt6.
+:::
+
+[Direct Download](https://download.opensuse.org/repositories/home:/pbek:/QOwnNotes/Debian_13)
+
 ## Debian 12.0
 
 Run the following shell commands to trust the repository.