Add developer local automation for PR linting - the whitespace rules are slowing throughput

Getting a PR in for readme or yaml changes sometimes takes longer than writing the PR with multiple iterations before the PR can merged.

Checking dev docs for a way to automate local linting before PR commits

```
2023-08-15 01:31:48 [INFO] Successfully found:[GITHUB_REPO], value:[pubsec-declarative-toolkit]
2023-08-15 01:31:48 [ERROR] Failed to get [GITHUB_TOKEN]!
2023-08-15 01:31:48 [ERROR] []
2023-08-15 01:31:48 [ERROR] Please set a [GITHUB_TOKEN] from the main workflow environment to take advantage of multiple status reports!

2023-08-15 01:31:53 [INFO] File:[/github/workspace/docs/landing-zone-v2/README.md]
2023-08-15 01:31:53 [ERROR] Found errors in [markdownlint] linter!
2023-08-15 01:31:53 [ERROR] Error code: 1. Command output:
------
/github/workspace/docs/landing-zone-v2/README.md:3[81](https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/actions/runs/5862548542/job/15894515244?pr=458#step:6:82) MD046/code-block-style Code block style [Expected: fenced; Actual: indented]
/github/workspace/docs/landing-zone-v2/README.md:3[87](https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/actions/runs/5862548542/job/15894515244?pr=458#step:6:88) MD046/code-block-style Code block style [Expected: fenced; Actual: indented]
/github/workspace/docs/landing-zone-v2/README.md:3[93](https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/actions/runs/5862548542/job/15894515244?pr=458#step:6:94) MD046/code-block-style Code block style [Expected: fenced; Actual: indented]
/github/workspace/docs/landing-zone-v2/README.md:399 MD046/code-block-style Code block style [Expected: fenced; Actual: indented]
/github/workspace/docs/landing-zone-v2/README.md:405 MD046/code-block-style Code block style [Expected: fenced; Actual: indented]
------
```

see for example a readme change in
https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/pull/458
https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/issues/457