feat: add support for KlusterAI provider and update documentation

[troels-im]

• Introduced support for KlusterAI chat completion models.
• Added necessary API key handling, cost calculations, and configuration.
• Created comprehensive tests for KlusterAI functionality to ensure reliability.
• Updated README and sidebars with KlusterAI information and usage examples.
• Cleaned up formatting across multiple files to enhance readability.

Title

Relevant issues

Pre-Submission checklist

Please complete all items before asking a LiteLLM maintainer to review your PR

• I have Added testing in the tests/litellm/ directory, Adding at least 1 test is a hard requirement - see details
• I have added a screenshot of my new test passing locally
• My PR passes all unit tests on (make test-unit)[https://docs.litellm.ai/docs/extras/contributing_code]
• My PR's scope is as isolated as possible, it only solves 1 specific problem

Type

🆕 New Feature
🐛 Bug Fix
🧹 Refactoring
📖 Documentation
🚄 Infrastructure
✅ Test

Changes

REPLACE DOCKER COMPOSE WITH

version: "3.11"
services:
  litellm:
    build:
      context: .
      dockerfile: docker/Dockerfile.non_root
    #      args:
    #        target: runtime
    #########################################
    ## Uncomment these lines to start proxy with a config.yaml file ##
    # volumes:
    #  - ./config.yaml:/app/config.yaml <<- this is missing in the docker-compose file currently
    # command:
    #  - "--config=/app/config.yaml"
    ##############################################
    ports:
      - "4000:4000" # Map the container port to the host, change the host port if necessary
    environment:
      DATABASE_URL: "postgresql://llmproxy:dbpassword9090@db:5432/litellm"
      STORE_MODEL_IN_DB: "True" # allows adding models to proxy via UI
    env_file:
      - .env # Load local .env file
    depends_on:
      - db # Indicates that this service depends on the 'db' service, ensuring 'db' starts first
    healthcheck: # Defines the health check configuration for the container
      test: [
          "CMD",
          "curl",
          "-f",
          "http://localhost:4000/health/liveliness || exit 1",
        ] # Command to execute for health check
      interval: 30s # Perform health check every 30 seconds
      timeout: 10s # Health check command times out after 10 seconds
      retries: 3 # Retry up to 3 times if health check fails
      start_period: 40s # Wait 40 seconds after container start before beginning health checks

  db:
    image: postgres:16
    restart: always
    environment:
      POSTGRES_DB: litellm
      POSTGRES_USER: llmproxy
      POSTGRES_PASSWORD: dbpassword9090
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data # Persists Postgres data across container restarts
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -d litellm -U llmproxy"]
      interval: 1s
      timeout: 5s
      retries: 10

  prometheus:
    image: prom/prometheus
    volumes:
      - prometheus_data:/prometheus
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
    ports:
      - "9090:9090"
    command:
      - "--config.file=/etc/prometheus/prometheus.yml"
      - "--storage.tsdb.path=/prometheus"
      - "--storage.tsdb.retention.time=15d"
    restart: always

volumes:
  prometheus_data:
    driver: local
  postgres_data:
    name: litellm_postgres_data # Named volume for Postgres data persistence