add package.json path checker

npm-packages/license_checker.yml

 before_script:
+  # Set PACKAGE_DIR to "." if not already defined. 
+  # PACKAGE_DIR should point to where the package.json file is
+  - PACKAGE_DIR=${PACKAGE_DIR:-"."}
+  # check if package.json exist on PACKAGE_DIR. If not, raise error
+  - test -f $PACKAGE_DIR/package.json || (echo "package.json not found in $PACKAGE_DIR" && exit 1)
   - npm install -g js-green-licenses
+  # check if js-green-licenses.json exist on PACKAGE_DIR. If not, inform user and continue
+  - test -f $PACKAGE_DIR/js-green-licenses.json || (echo "js-green-licenses.json not found in $PACKAGE_DIR" && echo "Continuing with default configuration")
  
 cache:
       paths:
@@ -11,6 +18,9 @@ license_check:
       - docker
     image: node:latest
     script:
+      # Change to the directory containing package.json
+      - cd $PACKAGE_DIR
+      # Install dependencies
       - npm install
       - jsgl --local ./ || exit 1
     only: