How to use rules_license on the envoy project ?

Hello,

I have to list all the external dependencies of a bazel built project ([envoy](https://github.com/envoyproxy/envoy)), with their name, version and license(s).

It seems `rules_license` would help me in this task, but I don't understand how to use it (I am new to bazel), do you have an example ?

Regarding my `envoy` specific use case, it seems all the required information is available to bazel: [envoy/bazel/repository_locations.bzl](https://github.com/envoyproxy/envoy/blob/main/bazel/repository_locations.bzl)

I have a `bazel` build command used to produce an envoy static binary with many 'filters' and 'options':

```
bazel \
build \
--define google_grpc=disabled \
--@envoy//bazel:http3=False \
--@envoy//source/extensions/wasm_runtime/v8:enabled=false \
[...]
@envoy//source/exe:envoy-static
```

Start with the requested rules_license usage and the linked Envoy bazel/repository_locations.bzl file, then inspect the rules_license documentation and examples. A useful result would show whether the stated Bazel command and Envoy dependency metadata can be handled, with a documented example or a clear explanation of the limitation.

Written by the indexing model from the issue text.