Add launcher update instructions to getting started

Added instructions for updating the launcher in the getting started guide.

docs/en/game/getting-started.md

@@ -139,6 +139,15 @@ Note that this assumes you put the launcher's binary you compiled earlier into `
 
     This can be done for example by adding the [Linux-port of the Windows Segoe-UI emoji font](https://github.com/mrbvrz/segoe-ui-linux)
 
+### **2d. Updating the Launcher**
+
+If you already build the launcher and want to update it, enter the BeamMP-Launcher folder where the build process happened and run these:
+```bash
+git fetch --tags
+git checkout 2.x.x
+```
+
+
 ---
 
 ## **3. Using BeamMP**