docs: add instructions for authenticating for system tests (#316)

This PR was generated using Autosynth. 🌈

Synth log will be available here:
https://source.cloud.google.com/results/invocations/fc1dd810-ea11-44c0-ab02-fa000827a405/targets

- [ ] To automatically regenerate this PR, check this box.

Source-Link: googleapis/synthtool@363fe30

packages/google-cloud-scheduler/CONTRIBUTING.md

@@ -37,6 +37,14 @@ accept your pull requests.
 1.  Title your pull request following [Conventional Commits](https://www.conventionalcommits.org/) styling.
 1.  Submit a pull request.
 
+### Before you begin
+
+1.  [Select or create a Cloud Platform project][projects]. 
+1.  [Enable the Google Cloud Scheduler API][enable_api]. 
+1.  [Set up authentication with a service account][auth] so you can access the
+    API from your local workstation.
+
+
 ## Running the tests
 
 1.  [Prepare your environment for Node.js setup][setup].
@@ -51,15 +59,17 @@ accept your pull requests.
         npm test
 
         # Run sample integration tests.
-        gcloud auth application-default login
         npm run samples-test
 
         # Run all system tests.
-        gcloud auth application-default login
         npm run system-test
 
 1.  Lint (and maybe fix) any changes:
 
         npm run fix
 
 [setup]: https://cloud.google.com/nodejs/docs/setup
+[projects]: https://console.cloud.google.com/project
+[billing]: https://support.google.com/cloud/answer/6293499#enable-billing
+[enable_api]: https://console.cloud.google.com/flows/enableapi?apiid=cloudscheduler.googleapis.com
+[auth]: https://cloud.google.com/docs/authentication/getting-started

packages/google-cloud-scheduler/README.md

@@ -95,8 +95,7 @@ console.log(`Created job: ${response.name}`);
 
 ## Samples
 
-Samples are in the [`samples/`](https://github.com/googleapis/nodejs-scheduler/tree/master/samples) directory. The samples' `README.md`
-has instructions for running the samples.
+Samples are in the [`samples/`](https://github.com/googleapis/nodejs-scheduler/tree/master/samples) directory. Each sample's `README.md` has instructions for running its sample.
 
 | Sample                      | Source Code                       | Try it |
 | --------------------------- | --------------------------------- | ------ |

packages/google-cloud-scheduler/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-scheduler.git",
-        "sha": "7f8b30c165d3de8beebb0e6704535b4eed7d817d"
+        "sha": "f145861882a40428d53ad15a5721f5b9f224f036"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "15013eff642a7e7e855aed5a29e6e83c39beba2a"
+        "sha": "363fe305e9ce34a6cd53951c6ee5f997094b54ee"
       }
     }
   ],
@@ -42,86 +42,5 @@
         "generator": "bazel"
       }
     }
-  ],
-  "generatedFiles": [
-    ".eslintignore",
-    ".eslintrc.json",
-    ".gitattributes",
-    ".github/ISSUE_TEMPLATE/bug_report.md",
-    ".github/ISSUE_TEMPLATE/feature_request.md",
-    ".github/ISSUE_TEMPLATE/support_request.md",
-    ".github/PULL_REQUEST_TEMPLATE.md",
-    ".github/release-please.yml",
-    ".github/workflows/ci.yaml",
-    ".gitignore",
-    ".jsdoc.js",
-    ".kokoro/.gitattributes",
-    ".kokoro/common.cfg",
-    ".kokoro/continuous/node10/common.cfg",
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-    ".kokoro/continuous/node12/common.cfg",
-    ".kokoro/continuous/node12/lint.cfg",
-    ".kokoro/continuous/node12/samples-test.cfg",
-    ".kokoro/continuous/node12/system-test.cfg",
-    ".kokoro/continuous/node12/test.cfg",
-    ".kokoro/docs.sh",
-    ".kokoro/lint.sh",
-    ".kokoro/populate-secrets.sh",
-    ".kokoro/presubmit/node10/common.cfg",
-    ".kokoro/presubmit/node12/common.cfg",
-    ".kokoro/presubmit/node12/samples-test.cfg",
-    ".kokoro/presubmit/node12/system-test.cfg",
-    ".kokoro/presubmit/node12/test.cfg",
-    ".kokoro/publish.sh",
-    ".kokoro/release/docs-devsite.cfg",
-    ".kokoro/release/docs-devsite.sh",
-    ".kokoro/release/docs.cfg",
-    ".kokoro/release/docs.sh",
-    ".kokoro/release/publish.cfg",
-    ".kokoro/samples-test.sh",
-    ".kokoro/system-test.sh",
-    ".kokoro/test.bat",
-    ".kokoro/test.sh",
-    ".kokoro/trampoline.sh",
-    ".kokoro/trampoline_v2.sh",
-    ".mocharc.js",
-    ".nycrc",
-    ".prettierignore",
-    ".prettierrc.js",
-    ".trampolinerc",
-    "CODE_OF_CONDUCT.md",
-    "CONTRIBUTING.md",
-    "LICENSE",
-    "README.md",
-    "api-extractor.json",
-    "linkinator.config.json",
-    "protos/google/cloud/scheduler/v1/cloudscheduler.proto",
-    "protos/google/cloud/scheduler/v1/job.proto",
-    "protos/google/cloud/scheduler/v1/target.proto",
-    "protos/google/cloud/scheduler/v1beta1/cloudscheduler.proto",
-    "protos/google/cloud/scheduler/v1beta1/job.proto",
-    "protos/google/cloud/scheduler/v1beta1/target.proto",
-    "protos/protos.d.ts",
-    "protos/protos.js",
-    "protos/protos.json",
-    "renovate.json",
-    "samples/README.md",
-    "src/index.ts",
-    "src/v1/cloud_scheduler_client.ts",
-    "src/v1/cloud_scheduler_client_config.json",
-    "src/v1/cloud_scheduler_proto_list.json",
-    "src/v1/index.ts",
-    "src/v1beta1/cloud_scheduler_client.ts",
-    "src/v1beta1/cloud_scheduler_client_config.json",
-    "src/v1beta1/cloud_scheduler_proto_list.json",
-    "src/v1beta1/index.ts",
-    "system-test/fixtures/sample/src/index.js",
-    "system-test/fixtures/sample/src/index.ts",
-    "system-test/install.ts",
-    "test/gapic_cloud_scheduler_v1.ts",
-    "test/gapic_cloud_scheduler_v1beta1.ts",
-    "tsconfig.json",
-    "webpack.config.js"
   ]
 }