Docs: update link to sample cfg following default branch change

README.md

@@ -24,7 +24,7 @@ $ make
 ## Configuration
 
 Create a configuration file, `tank.yaml`, based on:
-https://gitlab.servus.at/aura/tank/-/blob/master/contrib/sample-cfg.yaml
+https://gitlab.servus.at/aura/tank/-/blob/main/contrib/sample-cfg.yaml
 
 Make sure that the directory pointed to by `store.path` exists and is writeable
 for the user running the daemon.