docs: expand environment variables documentation with detailed tables
- Replace outdated SOKETI_ prefix references with PUSHER_ prefix throughout
- Add comprehensive environment variable tables organized by configuration section:
* Server Configuration (host, port, debug, mode)
* App Manager Configuration (driver, apps, caching)
* Adapter Configuration (local, cluster, redis, nats)
* Cache Configuration (memory, redis)
* Metrics Configuration (enabled, port, prefix)
* Database Configuration (MySQL, PostgreSQL, DynamoDB)
* Queue Configuration (sync, redis, sqs)
* SSL Configuration (enabled, cert path, key path)
* CORS Configuration (enabled, origins)
- Add practical examples for common setup scenarios:
* Simple default app setup
* JSON array of apps configuration
* Redis adapter integration
* Docker Compose environment variables
- Fix internal documentation links by removing .md extensions for consistency
- Update related resources section with corrected link formats
- Apply same documentation improvements to Turkish translation (yapilandirma.md)
Import existing documentation