feat: upgrade library to ga (#69)

* feat: upgrade library to ga

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: sofisl

packages/google-cloud-shell/.repo-metadata.json

@@ -4,7 +4,7 @@
   "product_documentation": "https://cloud.google.com/shell/",
   "client_documentation": "https://cloud.google.com/nodejs/docs/reference/shell/latest",
   "issue_tracker": "https://github.com/googleapis/nodejs-cloud-shell/issues",
-  "release_level": "stable",
+  "release_level": "ga",
   "language": "nodejs",
   "repo": "googleapis/nodejs-cloud-shell",
   "distribution_name": "@google-cloud/shell",

packages/google-cloud-shell/README.md

@@ -4,7 +4,7 @@
 
 # [Cloud Shell: Node.js Client](https://github.com/googleapis/nodejs-cloud-shell)
 
-[![release level](https://img.shields.io/badge/release%20level-stable-brightgreen.svg?style=flat)](https://cloud.google.com/terms/launch-stages)
+[![release level](https://img.shields.io/badge/release%20level-general%20availability%20%28GA%29-brightgreen.svg?style=flat)](https://cloud.google.com/terms/launch-stages)
 [![npm version](https://img.shields.io/npm/v/@google-cloud/shell.svg)](https://www.npmjs.org/package/@google-cloud/shell)
 
 
@@ -120,17 +120,18 @@ for versions compatible with Node.js 8.
 This library follows [Semantic Versioning](http://semver.org/).
 
 
-
-This library is considered to be **stable**. The code surface will not change in backwards-incompatible ways
+This library is considered to be **General Availability (GA)**. This means it
+is stable; the code surface will not change in backwards-incompatible ways
 unless absolutely necessary (e.g. because of critical security issues) or with
-an extensive deprecation period. Issues and requests against **stable** libraries
+an extensive deprecation period. Issues and requests against **GA** libraries
 are addressed with the highest priority.
 
 
 
 
 
 
+
 More Information: [Google Cloud Platform Launch Stages][launch_stages]
 
 [launch_stages]: https://cloud.google.com/terms/launch-stages