Merge pull request #21571 from mguetschow/guides-url-typo

guides: use absolute path to fix url

Author: crasbe

doc/guides/getting-started/install-wsl.mdx

@@ -8,7 +8,7 @@ The following guide is for Windows users only.
 
 It explains the process of installing Ubuntu LTS via Windows Subsystem for Linux (WSL) on a Windows machine.
 
-If you are using a different operating system, please refer to [the general guide on how to use RIOT](getting-started/installing).
+If you are using a different operating system, please refer to [the general guide on how to use RIOT](/getting-started/installing).
 :::
 
 ## Install Ubuntu LTS