Update README and UPGRADING

Author: marickvantuil

README.md

@@ -61,10 +61,16 @@ This package requires Laravel 10 or 11.
 composer require stackkit/laravel-google-cloud-scheduler
 ```
 
-2 - Define the `STACKKIT_CLOUD_SCHEDULER_APP_URL` environment variable. This should be the URL defined in the `URL` field of your Cloud Scheduler job.
+2 - Define environment variables
 
-```
-STACKKIT_CLOUD_SCHEDULER_APP_URL=https://yourdomainname.com/cloud-scheduler-job
+`CLOUD_SCHEDULER_APP_URL` - This should be the URL defined in the `URL` field of your Cloud Scheduler job.
+
+`CLOUD_SCHEDULER_SERVICE_ACCOUNT` - The e-mail address of the service account invocating the task.
+
+Optionally, you may publish the configuration file:
+
+```bash
+php artisan vendor:publish --tag-cloud-scheduler-config
 ```
 
 3 - Ensure PHP executable is in open_basedir. This is required for the package to run Artisan commands.

UPGRADING.md

@@ -0,0 +1,19 @@
+# From 2.x to 3.x
+
+Support for Laravel 6, 7, 8, and 9 has been dropped. The minimum supported version is now Laravel 10.
+
+## Environment changes (Impact: high)
+
+Publish the new configuration file:
+
+```bash
+php artisan vendor:publish --tag=cloud-scheduler-config
+```
+
+Change the environment variables names:
+
+- `STACKKIT_CLOUD_SCHEDULER_APP_URL` -> `CLOUD_SCHEDULER_APP_URL`
+
+Add the following environment variable:
+
+- `CLOUD_SCHEDULER_SERVICE_ACCOUNT` - The e-mail address of the service account invocating the task.