build(docs-infra): upgrade @angular/cli to 8.0.0-beta.18 (#29926)

This commit also changes the config files and their layout to
(reasonably closely) match what the cli would generate for a new app.

Related Jira issue: [TOOL-815](https://angular-team.atlassian.net/browse/TOOL-815)

PR Close #29926

aio/karma.conf.js

@@ -0,0 +1,33 @@
+// Karma configuration file, see link for more information
+// https://karma-runner.github.io/1.0/config/configuration-file.html
+
+module.exports = function (config) {
+  config.set({
+    basePath: '',
+    frameworks: ['jasmine', '@angular-devkit/build-angular'],
+    plugins: [
+      require('karma-jasmine'),
+      require('karma-chrome-launcher'),
+      require('karma-jasmine-html-reporter'),
+      require('karma-coverage-istanbul-reporter'),
+      require('@angular-devkit/build-angular/plugins/karma')
+    ],
+    client: {
+      clearContext: false // leave Jasmine Spec Runner output visible in browser
+    },
+    coverageIstanbulReporter: {
+      dir: require('path').join(__dirname, './coverage/site'),
+      reports: ['html', 'lcovonly', 'text-summary'],
+      fixWebpackSourcePaths: true
+    },
+    reporters: ['progress', 'kjhtml'],
+    port: 9876,
+    colors: true,
+    logLevel: config.LOG_INFO,
+    autoWatch: true,
+    browsers: ['Chrome'],
+    browserNoActivityTimeout: 60000,
+    singleRun: false,
+    restartOnFileChange: true
+  });
+};