Update URL in the migration script

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

cookiecutter/migrate.py

@@ -10,9 +10,9 @@
 
 To run it, the simplest way is to fetch it from GitHub and run it directly:
 
-    curl -sSL https://raw.githubusercontent.com/frequenz-floss/frequenz-repo-config-python/v0.10.0/cookiecutter/migrate.py | python3
+    curl -sSL https://raw.githubusercontent.com/frequenz-floss/frequenz-repo-config-python/<tag>/cookiecutter/migrate.py | python3
 
-Make sure the version you want to migrate to is correct in the URL.
+Make sure to replace the `<tag>` to the version you want to migrate to in the URL.
 
 For jumping multiple versions you should run the script multiple times, once
 for each version.