[Metro AI Suite] IBVS: Add how to use GPU for inference doc

[rohitkatakol]

Description

Add how to use GPU for inference docs. Skipping NPU docs as of now since the model person-vehicle-bike-detection-2004 is currently not supported on NPU devices, as indicated on the OpenVINO supported models page: https://docs.openvino.ai/2025/documentation/compatibility-and-support/supported-models.html
Updated logic to correctly volume mount CPU/GPU config pipeline for helm deployment

Fixes # https://jira.devtools.intel.com/browse/ITEP-85663

Any Newly Introduced Dependencies

No new dependency introduced

How Has This Been Tested?

Checked the document preview in Visual studio for any document errors. Ran the IBVS application on GPU and CPU device and checked the corresponding memory

Checklist:

• I agree to use the APACHE-2.0 license for my code changes.
• I have not introduced any 3rd party components incompatible with APACHE-2.0.
• I have not included any company confidential information, trade secret, password or security token.
• I have performed a self-review of my code.