Enhance .env.example with more comprehensive examples

This commit enriches the .env.example file in the scripts/govtool directory.
The updated examples in the file provide clearer guidance on environment setup,
reflecting a more comprehensive and realistic configuration for the GovTool stack.
These enhancements are designed to offer a more user-friendly setup experience,
especially for new developers or contributors who are configuring their environment
for the first time.

Technical Details:
- Expanded the environment variable examples, providing more detailed placeholders.
- Included variables for database passwords, Traefik Let's Encrypt email, Google Tag Manager ID, Sentry DSN for backend and general use, NGINX basic authentication, and various Grafana settings (admin password, Slack recipient, webhook, and OAuth token).

scripts/govtool/.env.example

@@ -4,12 +4,26 @@ export AWS_PROFILE=govtool
 
 export ENVIRONMENT="dev"
 export CARDANO_NETWORK="sanchonet"
-export SLACK_WEBHOOK_URL=<slack webhook url>
+export SLACK_WEBHOOK_URL=<slack_webhook_url>
 
 export DBSYNC_POSTGRES_USER="postgres"
-export DBSYNC_POSTGRES_PASSWORD=""
+export DBSYNC_POSTGRES_PASSWORD=<dbsync_postgres_password>
 export DBSYNC_POSTGRES_DB="cexplorer"
+
 export FAKEDBSYNC_POSTGRES_DB="govtool"
 export FAKEDBSYNC_POSTGRES_USER="test"
-export FAKEDBSYNC_POSTGRES_PASSWORD="test"
-export TRAEFIK_LE_EMAIL=""
+export FAKEDBSYNC_POSTGRES_PASSWORD=<fakedbsync_postgres_password>
+
+export TRAEFIK_LE_EMAIL=<traefik_le_email>
+
+export GTM_ID=blank
+
+export SENTRY_DSN_BACKEND=blank
+export SENTRY_DSN=blank
+
+export NGINX_BASIC_AUTH=<nginx_basic_auth>
+
+export GRAFANA_ADMIN_PASSWORD=<grafana_admin_password>
+export GRAFANA_SLACK_RECIPIENT=<grafana_slack_recipient>
+export GRAFANA_SLACK_WEBHOOK=<grafana_slack_webhook>
+export GRAFANA_SLACK_OAUTH_TOKEN=<grafana_slack_oauth_token>