chore: fix broken docs link

README.md

@@ -24,7 +24,7 @@ If you wish to translate ReVanced Manager, we're accepting translations on [Crow
 ## 🛠️ Building Manager from source
 1. Setup flutter environment for your [platform](https://docs.flutter.dev/get-started/install)
 2. Clone the repository locally
-3. Add your github token in gradle.properties like [this](https://github.com/revanced/revanced-manager/blob/main/docs/4_building.md)
+3. Add your github token in gradle.properties like [this](/docs/4_building.md)
 4. Open the project in terminal
 5. Run `flutter pub get` in terminal
 6. Then `flutter packages pub run build_runner build --delete-conflicting-outputs` (Must be done on each git pull)