Add Navigation Highlighting for Build Rules

Created by: sdwilsh

Test Plan: Ensured that following pages were properly selected when viewed:

• http://localhost:9811/rule/export_file.html
• http://localhost:9811/rule/genrule.html
• http://localhost:9811/rule/remote_file.html
• http://localhost:9811/rule/worker_tool.html
• http://localhost:9811/rule/zip_file.html
• http://localhost:9811/rule/android_aar.html
• http://localhost:9811/rule/android_binary.html
• http://localhost:9811/rule/android_build_config.html
• http://localhost:9811/rule/android_instrumentation_apk.html
• http://localhost:9811/rule/android_instrumentation_test.html
• http://localhost:9811/rule/android_library.html
• http://localhost:9811/rule/android_manifest.html
• http://localhost:9811/rule/android_prebuilt_aar.html
• http://localhost:9811/rule/android_resource.html
• http://localhost:9811/rule/apk_genrule.html
• http://localhost:9811/rule/gen_aidl.html
• http://localhost:9811/rule/keystore.html
• http://localhost:9811/rule/ndk_library.html
• http://localhost:9811/rule/prebuilt_jar.html
• http://localhost:9811/rule/prebuilt_native_library.html
• http://localhost:9811/rule/project_config.html
• http://localhost:9811/rule/cxx_binary.html
• http://localhost:9811/rule/cxx_library.html
• http://localhost:9811/rule/cxx_precompiled_header.html
• http://localhost:9811/rule/cxx_test.html
• http://localhost:9811/rule/prebuilt_cxx_library.html
• http://localhost:9811/rule/prebuilt_cxx_library_group.html
• http://localhost:9811/rule/d_binary.html
• http://localhost:9811/rule/d_library.html
• http://localhost:9811/rule/d_test.html
• http://localhost:9811/rule/go_binary.html
• http://localhost:9811/rule/go_library.html
• http://localhost:9811/rule/go_test.html
• http://localhost:9811/rule/groovy_library.html
• http://localhost:9811/rule/halide_library.html
• http://localhost:9811/rule/haskell_binary.html
• http://localhost:9811/rule/haskell_library.html
• http://localhost:9811/rule/prebuilt_haskell_library.html
• http://localhost:9811/rule/apple_asset_catalog.html
• http://localhost:9811/rule/apple_binary.html
• http://localhost:9811/rule/apple_bundle.html
• http://localhost:9811/rule/apple_library.html
• http://localhost:9811/rule/apple_package.html
• http://localhost:9811/rule/apple_resource.html
• http://localhost:9811/rule/apple_test.html
• http://localhost:9811/rule/core_data_model.html
• http://localhost:9811/rule/java_binary.html
• http://localhost:9811/rule/java_library.html
• http://localhost:9811/rule/java_test.html
• http://localhost:9811/rule/prebuilt_jar.html
• http://localhost:9811/rule/prebuilt_native_library.html
• http://localhost:9811/rule/cxx_lua_extension.html
• http://localhost:9811/rule/lua_binary.html
• http://localhost:9811/rule/lua_library.html
• http://localhost:9811/rule/prebuilt_python_library.html
• http://localhost:9811/rule/python_binary.html
• http://localhost:9811/rule/python_library.html
• http://localhost:9811/rule/python_test.html
• http://localhost:9811/rule/rust_binary.html
• http://localhost:9811/rule/rust_library.html
• http://localhost:9811/rule/rust_test.html
• http://localhost:9811/rule/prebuilt_rust_library.html
• http://localhost:9811/rule/csharp_library.html
• http://localhost:9811/rule/prebuilt_dotnet_library.html