build(docs-infra): upgrade cli command docs sources to c91579a2e

Updating [angular#master](https://github.com/angular/angular/tree/master) from [cli-builds#master](https://github.com/angular/cli-builds/tree/master).
Relevant changes in [commit range](angular/cli-builds@1631f7d...c91579a):

**Modified**
- help/build.json

**Removed**
- help/eject.json

Closes angular#28772
Closes angular#28795
Closes angular#28816
Closes angular#28859
Closes angular#28882

aio/package.json

@@ -19,7 +19,7 @@
     "build-local": "yarn ~~build",
     "prebuild-with-ivy": "yarn setup-local && yarn ivy-ngcc",
     "build-with-ivy": "node scripts/build-with-ivy",
-    "extract-cli-command-docs": "node tools/transforms/cli-docs-package/extract-cli-commands.js 1631f7d62",
+    "extract-cli-command-docs": "node tools/transforms/cli-docs-package/extract-cli-commands.js c91579a2e",
     "lint": "yarn check-env && yarn docs-lint && ng lint && yarn example-lint && yarn tools-lint",
     "test": "yarn check-env && ng test",
     "pree2e": "yarn check-env && yarn update-webdriver",