feat: publish stardocs on releases (#266)

They will appear on BCR, similar to https://registry.bazel.build/docs/bazelrc-preset.bzl/1.4.0

Author: alexeagle

.bcr/source.template.json

@@ -1,5 +1,6 @@
 {
   "integrity": "**leave this alone**",
   "strip_prefix": "{REPO}-{VERSION}",
+  "docs_url": "https://github.com/{OWNER}/{REPO}/releases/download/{TAG}/{REPO}-{TAG}.docs.tar.gz",
   "url": "https://github.com/{OWNER}/{REPO}/releases/download/{TAG}/{REPO}-{TAG}.tar.gz"
 }

.github/workflows/release_prep.sh

@@ -13,6 +13,14 @@ ARCHIVE="rules_ruby-$TAG.tar.gz"
 git archive --format=tar --prefix=${PREFIX}/ ${TAG} | gzip > $ARCHIVE
 SHA=$(shasum -a 256 $ARCHIVE | awk '{print $1}')
 
+# Add generated API docs to the release, see https://github.com/bazelbuild/bazel-central-registry/issues/5593
+docs="$(mktemp -d)"; targets="$(mktemp)"
+bazel --output_base="$docs" query --output=label --output_file="$targets" 'kind("starlark_doc_extract rule", //rails:all //ruby:all)'
+bazel --output_base="$docs" build --target_pattern_file="$targets"
+tar --create --auto-compress \
+    --directory "$(bazel --output_base="$docs" info bazel-bin)" \
+    --file "$GITHUB_WORKSPACE/${ARCHIVE%.tar.gz}.docs.tar.gz" .
+
 # The stdout of this program will be used as the top of the release notes for this release.
 cat << EOF
 ## Using Bzlmod with Bazel 7-8

rails/BUILD.bazel

@@ -10,3 +10,9 @@ bzl_library(
         "//rails/private:rails_test_factory",
     ],
 )
+
+starlark_doc_extract(
+    name = "rails_test_factory.doc_extract",
+    src = "rails_test_factory.bzl",
+    deps = [":rails_test_factory"],
+)

ruby/BUILD

@@ -24,6 +24,12 @@ bzl_library(
     ],
 )
 
+starlark_doc_extract(
+    name = "defs.doc_extract",
+    src = "defs.bzl",
+    deps = [":defs"],
+)
+
 bzl_library(
     name = "deps",
     srcs = ["deps.bzl"],
@@ -34,6 +40,12 @@ bzl_library(
     ],
 )
 
+starlark_doc_extract(
+    name = "deps.doc_extract",
+    src = "deps.bzl",
+    deps = [":deps"],
+)
+
 bzl_library(
     name = "extensions",
     srcs = ["extensions.bzl"],