Document using `bundle-modules = [ "go" ]` for Go packages that don't vendor dependencies

**What I'd like:**

There currently isn't any good documentation on using `bundle-modules = ["go"]` for packages that are pulled in and _don't_ vendor their own dependencies (like `hotdog`).

We should write up a snippet on using this system on the buildsys markdown so that package authors can reference it when building in new packages.

**Any alternatives you've considered:**

There is _some_ documentation on this directly in the buildsys code:

https://github.com/bottlerocket-os/bottlerocket/blob/4b8a132fd34205408afb0683dd157f6856a50d13/tools/buildsys/src/manifest.rs#L36-L39

which was added as part of the initial feature add: https://github.com/bottlerocket-os/bottlerocket/pull/2378

But this should really be in the markdown docs itself since we can't expect package authors to read the buildsys code.

Start by reading the existing guidance in tools/buildsys/src/manifest.rs around lines 36-39 and inspect the buildsys markdown documentation. Add a snippet explaining how package authors can use bundle-modules = ["go"] for Go packages that do not vendor dependencies, then verify that the documentation clearly covers the hotdog-style case.

Written by the indexing model from the issue text.