fix(docs): add docs.metadata.json for product neutral guides (googleapis#15960)

Author: bshaffer

ci/cloudbuild/builds/publish-docs.sh

@@ -94,6 +94,8 @@ function stage_docfx() {
   local path="${binary_dir}/google/cloud/${feature}/docfx"
   if [[ "${feature}" == "common" ]]; then
     path="${binary_dir}/google/cloud/docfx"
+  elif [[ "${feature}" == "guides" ]]; then
+    path="${binary_dir}/product-neutral-guides/docfx"
   fi
 
   echo "path=${path}" >"${log}"
@@ -120,6 +122,7 @@ io::log "bucket:  gs://${docfx_bucket}"
 # have documentation, such as `experimental-storage_grpc`. These are harmless,
 # as the `stage_docfx()` function skips missing directories without an error.
 uploaded=(common)
+uploaded+=(guides)
 uploaded+=("${FEATURE_LIST[@]}")
 echo "${uploaded[@]}" | xargs -P "$(nproc)" -n 1 \
   bash -c "stage_docfx \"\${0}\" \"${docfx_bucket}\" cmake-out \"cmake-out/\${0}.docfx.log\""

docfx/product-neutral-guides/CMakeLists.txt

@@ -51,6 +51,11 @@ set(TOC_ITEMS ${toc_items})
 set(toc_file "${output_dir}/toc.yml")
 configure_file("${CMAKE_CURRENT_SOURCE_DIR}/toc.yml.in" "${toc_file}" @ONLY)
 
+set(metadata_file "${output_dir}/docs.metadata.json")
+configure_file("${CMAKE_CURRENT_SOURCE_DIR}/docs.metadata.json.in"
+               "${metadata_file}" @ONLY)
+list(APPEND copied_files "${metadata_file}")
+
 add_custom_target(product-neutral-guides-docs DEPENDS ${copied_files})
 
 add_dependencies(all-docfx product-neutral-guides-docs)

docfx/product-neutral-guides/docs.metadata.json.in

@@ -0,0 +1,5 @@
+{
+    "language": "cpp",
+    "name": "product-neutral-guides",
+    "version": "@PROJECT_VERSION@"
+}