Rules docs Gazelle

rules_docs_gazelle adds a docs_filegroup to existing Bazel packages that contain a README.md. The generated rule loads its macro from rules_docs.

Add rules_docs as a normal dependency and this generator as a development dependency:

bazel_dep(name = "rules_docs", version = "<VERSION>")
bazel_dep(
    name = "rules_docs_gazelle",
    version = "<VERSION>",
    dev_dependency = True,
)

Add the public language target to the repository’s custom Gazelle binary:

load("@gazelle//:def.bzl", "gazelle_binary")

gazelle_binary(
    name = "gazelle_binary",
    languages = [
        "@rules_docs_gazelle//gazelle",
    ],
)

The extension only operates in directories where both a BUILD file and a README.md already exist. Newly generated rules use glob(["*.md"]) and are visible only to their nearest ancestor Bazel package. Existing srcs, deps, visibility, and prefix attributes are preserved.

The public @rules_docs_gazelle//gazelle:gazelle_docs binary contains only this extension and can update a nested workspace without initializing unrelated language plugins from its parent repository.