[FR]: Extend docs to explain difference to other/similar/mirrored functions

### What is the current behavior?

_No response_

### Describe the feature

Some of your rules such as [expand_template](https://docs.aspect.build/rulesets/aspect_bazel_lib/docs/expand_template/) are also available with the same name and interface in other projects such as [skylib's expand template](https://github.com/bazelbuild/bazel-skylib/blob/main/rules/expand_template.bzl). Maybe you could provide a brief explanation about the main differences between your rules and the others similar as you do it in https://docs.aspect.build/rulesets/aspect_bazel_lib/docs/tar

Start with the expand_template documentation linked in the issue and compare its interface with skylib's expand_template. Review the existing tar documentation for the expected comparison style, then document the main differences between the similar rules. Done means the expand_template page briefly explains how it differs from the other implementation.

Written by the indexing model from the issue text.