Symbolic Macros should generate docs pretty much exactly like rules

Symbolic Macros (https://bazel.build/extending/macros) seems like they are meant to cover the case where you really want to create a "rule", but is easier to actually compose it out of one or more other rules. But the generated documentation leaks this details, it calls out that it is a "macro" and not a "rule", but why should the *users* of the thing care? They should be treating it just like a rule.

- The generated docs for `name` calls out it is a macro vs a rule.
- The generated docs for `name` also calls out there could be multiple subtargets, but isn't that an implementation detail?
- The summary block for the macro includes the `*` before the `name`, why? Since everything has to be named like a rule, why is this needed? A rule's docs don't include a `*`?

Reproduce the generated documentation for a symbolic macro and compare it with the corresponding rule documentation, focusing on the name wording, subtarget note, and summary marker described in the issue. Trace the symbolic-macro documentation generation path and its existing tests; done means macro output presents the user-facing API like a rule without those implementation details.

Written by the indexing model from the issue text.