docs: edit golden file error description (angular#34871)

jbogarthyde · matsko · commit 5b77e67dff7b · 2020-01-21T14:25:38.000-05:00
PR Close angular#34871
diff --git a/docs/PUBLIC_API.md b/docs/PUBLIC_API.md
@@ -47,10 +47,11 @@ Our peer dependencies (such as TypeScript, Zone.js, or RxJS) are not considered
 <a name="golden-files"></a>
 
 ## Golden files
-Angular tracks the status of the public API in *golden files*. These files are stored in [tools/public_api_guard/](../tools/public_api_guard) and are maintained with a tool called [TS API Guardian](https://www.npmjs.com/package/ts-api-guardian).
-If you modify any part of a public API in one of the supported public packages, you must update the golden files that track the public API surface.
-If the golden files are not updated correctly, our test suite will detect the problem and the PR will fail to pass the tests.
-In such cases, a test error message will provide instructions for a command that updates the golden files.
+
+Angular tracks the status of the public API in a *golden file*, maintained with a tool called the *public API guard*.
+If you modify any part of a public API in one of the supported public packages, the PR can fail a test in CI with an error message that instructs you to accept the golden file.
+
+The public API guard provides a Bazel target that updates the current status of a given package. If you add to or modify the public API in any way, you must use [yarn](https://yarnpkg.com/) to execute the Bazel target in your terminal shell of choice (a recent version of `bash` is recommended).
 
 ```shell
 yarn bazel run //tools/public_api_guard:<modified_package>_api.accept
