Create a feature matrix listing the supported features from flashinfer-ai/flashinfer that have been enabled for rocm-flashinfer

[diptorupd]

The current list of TODOs in our README is not comprehensive and does not help much in terms of understanding what features from upstream are supported on ROCm.

We need to come up with a proper API-level feature matrix that will help users understand the feature gaps.

An example of what can be done: https://intelpython.github.io/dpnp/reference/comparison.html