docs(nodejs): version support policy edits (#1346) (#67)

Author: gcf-owl-bot[bot]

packages/google-cloud-shell/README.md

@@ -99,21 +99,21 @@ also contains samples.
 Our client libraries follow the [Node.js release schedule](https://nodejs.org/en/about/releases/).
 Libraries are compatible with all current _active_ and _maintenance_ versions of
 Node.js.
+If you are using an end-of-life version of Node.js, we recommend that you update
+as soon as possible to an actively supported LTS version.
 
-Client libraries targeting some end-of-life versions of Node.js are available, and
-can be installed via npm [dist-tags](https://docs.npmjs.com/cli/dist-tag).
-The dist-tags follow the naming convention `legacy-(version)`.
-
-_Legacy Node.js versions are supported as a best effort:_
+Google's client libraries support legacy versions of Node.js runtimes on a
+best-efforts basis with the following warnings:
 
-* Legacy versions will not be tested in continuous integration.
-* Some security patches may not be able to be backported.
-* Dependencies will not be kept up-to-date, and features will not be backported.
+* Legacy versions are not tested in continuous integration.
+* Some security patches and features cannot be backported.
+* Dependencies cannot be kept up-to-date.
 
-#### Legacy tags available
-
-* `legacy-8`: install client libraries from this dist-tag for versions
-  compatible with Node.js 8.
+Client libraries targeting some end-of-life versions of Node.js are available, and
+can be installed through npm [dist-tags](https://docs.npmjs.com/cli/dist-tag).
+The dist-tags follow the naming convention `legacy-(version)`.
+For example, `npm install @google-cloud/shell@legacy-8` installs client libraries
+for versions compatible with Node.js 8.
 
 ## Versioning