feat(observability): add obs_config option and document stdout export

- Add obs_config parameter to config struct with default path
- Document how to modify use_stdout value in README.md
- Support configuring observability via file or environment variables

This change helps users configure telemetry output destination for better
observability options in different deployment scenarios.

.docker/observability/README.md

@@ -0,0 +1,101 @@
+# Observability
+
+This directory contains the observability stack for the application. The stack is composed of the following components:
+
+- Prometheus
+- Grafana
+- Loki
+- Jaeger
+- Otel Collector
+
+## Prometheus
+
+Prometheus is a monitoring and alerting toolkit. It scrapes metrics from instrumented jobs, either directly or via an
+intermediary push gateway for short-lived jobs. It stores all scraped samples locally and runs rules over this data to
+either aggregate and record new time series from existing data or generate alerts. Grafana or other API consumers can be
+used to visualize the collected data.
+
+## Grafana
+
+Grafana is a multi-platform open-source analytics and interactive visualization web application. It provides charts,
+graphs, and alerts for the web when connected to supported data sources.
+
+## Loki
+
+Loki is a horizontally-scalable, highly-available, multi-tenant log aggregation system inspired by Prometheus. It is
+designed to be very cost-effective and easy to operate. It does not index the contents of the logs, but rather a set of
+labels for each log stream.
+
+## Jaeger
+
+Jaeger is a distributed tracing system released as open source by Uber Technologies. It is used for monitoring and
+troubleshooting microservices-based distributed systems, including:
+
+- Distributed context propagation
+- Distributed transaction monitoring
+- Root cause analysis
+- Service dependency analysis
+- Performance / latency optimization
+
+## Otel Collector
+
+The OpenTelemetry Collector offers a vendor-agnostic implementation on how to receive, process, and export telemetry
+data. It removes the need to run, operate, and maintain multiple agents/collectors in order to support open-source
+observability data formats (e.g. Jaeger, Prometheus, etc.) sending to one or more open-source or commercial back-ends.
+
+## How to use
+
+To deploy the observability stack, run the following command:
+
+```bash
+docker-compose -f docker-compose.yml -f docker-compose.override.yml up -d
+```
+
+To access the Grafana dashboard, navigate to `http://localhost:3000` in your browser. The default username and password
+are `admin` and `admin`, respectively.
+
+To access the Jaeger dashboard, navigate to `http://localhost:16686` in your browser.
+
+To access the Prometheus dashboard, navigate to `http://localhost:9090` in your browser.
+
+## How to stop
+
+To stop the observability stack, run the following command:
+
+```bash
+docker-compose -f docker-compose.yml -f docker-compose.override.yml down
+```
+
+## How to remove data
+
+To remove the data generated by the observability stack, run the following command:
+
+```bash
+docker-compose -f docker-compose.yml -f docker-compose.override.yml down -v
+```
+
+## How to configure
+
+To configure the observability stack, modify the `docker-compose.override.yml` file. The file contains the following
+
+```yaml
+services:
+  prometheus:
+    environment:
+      - PROMETHEUS_CONFIG_FILE=/etc/prometheus/prometheus.yml
+    volumes:
+      - ./prometheus.yml:/etc/prometheus/prometheus.yml
+
+  grafana:
+    environment:
+      - GF_SECURITY_ADMIN_PASSWORD=admin
+    volumes:
+      - ./grafana/provisioning:/etc/grafana/provisioning
+```
+
+The `prometheus` service mounts the `prometheus.yml` file to `/etc/prometheus/prometheus.yml`. The `grafana` service
+mounts the `grafana/provisioning` directory to `/etc/grafana/provisioning`. You can modify these files to configure the
+observability stack.
+
+
+