chore(env): Add .env.example for dotCMS Symfony setup

- Introduced a new .env.example file with default environment variables for dotCMS Symfony.
- Included placeholders for APP_ENV, DATABASE_URL, MESSENGER_TRANSPORT_DSN, and DotCMS API configuration.

Author: fmontes

examples/dotcms-symfony/.env.example

@@ -0,0 +1,45 @@
+# In all environments, the following files are loaded if they exist,
+# the latter taking precedence over the former:
+#
+#  * .env                contains default values for the environment variables needed by the app
+#  * .env.local          uncommitted file with local overrides
+#  * .env.$APP_ENV       committed environment-specific defaults
+#  * .env.$APP_ENV.local uncommitted environment-specific overrides
+#
+# Real environment variables win over .env files.
+#
+# DO NOT DEFINE PRODUCTION SECRETS IN THIS FILE NOR IN ANY OTHER COMMITTED FILES.
+# https://symfony.com/doc/current/configuration/secrets.html
+#
+# Run "composer dump-env prod" to compile .env files for production use (requires symfony/flex >=1.2).
+# https://symfony.com/doc/current/best_practices.html#use-environment-variables-for-infrastructure-configuration
+
+###> symfony/framework-bundle ###
+APP_ENV=dev
+APP_SECRET=
+###< symfony/framework-bundle ###
+
+###> doctrine/doctrine-bundle ###
+# Format described at https://www.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url
+# IMPORTANT: You MUST configure your server version, either here or in config/packages/doctrine.yaml
+#
+# DATABASE_URL="sqlite:///%kernel.project_dir%/var/data.db"
+# DATABASE_URL="mysql://app:!ChangeMe!@127.0.0.1:3306/app?serverVersion=8.0.32&charset=utf8mb4"
+# DATABASE_URL="mysql://app:!ChangeMe!@127.0.0.1:3306/app?serverVersion=10.11.2-MariaDB&charset=utf8mb4"
+DATABASE_URL="postgresql://app:!ChangeMe!@127.0.0.1:5432/app?serverVersion=16&charset=utf8"
+###< doctrine/doctrine-bundle ###
+
+###> symfony/messenger ###
+# Choose one of the transports below
+# MESSENGER_TRANSPORT_DSN=amqp://guest:guest@localhost:5672/%2f/messages
+# MESSENGER_TRANSPORT_DSN=redis://localhost:6379/messages
+MESSENGER_TRANSPORT_DSN=doctrine://default?auto_setup=0
+###< symfony/messenger ###
+
+###> symfony/mailer ###
+MAILER_DSN=null://null
+###< symfony/mailer ###
+
+
+DOTCMS_HOST=your-dotcms-instance-url
+DOTCMS_API_KEY=your-dotcms-instance-token