docs: Update README with TLS instructions

Signed-off-by: Mahendra Paipuri <[email protected]>

README.md

@@ -75,6 +75,16 @@ DCGM_FI_DEV_MEMORY_TEMP{gpu="0", UUID="GPU-604ac76c-d9cf-fef3-62e9-d92044ab6e52"
 To integrate DCGM-Exporter with Prometheus and Grafana, see the full instructions in the [user guide](https://docs.nvidia.com/datacenter/cloud-native/gpu-telemetry/latest/).
 `dcgm-exporter` is deployed as part of the GPU Operator. To get started with integrating with Prometheus, check the Operator [user guide](https://docs.nvidia.com/datacenter/cloud-native/gpu-operator/getting-started.html#gpu-telemetry).
 
+### TLS and Basic Auth
+
+Exporter supports TLS and basic auth using [exporter-toolkit](https://github.com/prometheus/exporter-toolkit). To use TLS and/or basic auth, users need to use `--web-config-file` CLI flag as follows
+
+```
+dcgm-exporter --web-config-file=web-config.yaml
+```
+
+A sample `web-config.yaml` file can be fetched from [exporter-toolkit repository](https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-config.yml). The reference of the `web-config.yaml` file can be consulted in the [docs](https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md).
+
 ### Building from Source
 
 In order to build dcgm-exporter ensure you have the following: