documentation: Bump version

Author: nekohasekai

docs/changelog.md

@@ -2,6 +2,17 @@
 icon: material/alert-decagram
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+#### 1.13.0-beta.1
+
+* Add system interface support for Tailscale endpoint **1**
+* Fixes and improvements
+
+**1**:
+
+Tailscale endpoint can now create a system TUN interface to handle traffic directly.
+
+See [Tailscale endpoint](/configuration/endpoint/tailscale/#system_interface).
+
 #### 1.12.15
 
 * Fixes and improvements