fix: scope git config to local repo, allow env var overrides

- Drop --global from `git config pull.rebase false` to avoid mutating
  the user's global git configuration.
- Use ${VAR:-default} for TEMPLATE_URL and BRANCH so they can be
  overridden via environment variables without editing the script.

Author: blooop

scripts/update_from_template.sh

@@ -1,10 +1,10 @@
 #! /bin/bash
 set -eo pipefail
 
-TEMPLATE_URL="https://github.com/blooop/python_template.git"
-BRANCH="feature/update_from_template"
+TEMPLATE_URL="${TEMPLATE_URL:-https://github.com/blooop/python_template.git}"
+BRANCH="${BRANCH:-feature/update_from_template}"
 
-git config --global pull.rebase false
+git config pull.rebase false
 git remote remove template 2>/dev/null || true
 git remote add template "$TEMPLATE_URL"
 git fetch --all