docs: update of landing page and backup pages (angular#47047)

Updates the angular.io landing page with new messaging
and new images. The Quick-start app has been updated
to demonstrate a minimalist Angular app and the value
proposition content has been updated.

PR Close angular#47047

.gitignore

@@ -56,3 +56,4 @@ baseline.json
 
 # Husky
 .husky/_
+aio/content/examples/.DS_Store

.pullapprove.yml

@@ -858,6 +858,7 @@ groups:
           'aio/content/examples/getting-started-v0/**/{*,.*}',
           'aio/content/examples/getting-started/**/{*,.*}',
           'aio/content/start/**/{*,.*}',
+          'aio/content/guide/quick-start.md',
           'aio/content/images/guide/start/**/{*,.*}',
           'aio/content/examples/what-is-angular/**/{*,.*}',
           'aio/content/guide/what-is-angular.md'
@@ -875,6 +876,7 @@ groups:
     conditions:
       - >
         contains_any_globs(files.exclude("aio/content/marketing/contributors.json"), [
+          'aio/content/examples/marketing-first-app/**/{*,.*}',
           'aio/content/guide/roadmap.md',
           'aio/content/marketing/**/{*,.*}',
           'aio/content/images/marketing/**/{*,.*}',

aio/content/demos/first-app/.gitignore

@@ -1,4 +1,7 @@
 # See http://help.github.com/ignore-files/ for more about ignoring files.
+# git should ignore the cached files
+.angular
+node_modules
 
 # Compiled output
 /dist

aio/content/demos/first-app/angular.json

@@ -16,14 +16,12 @@
             "outputPath": "dist/addOneButton",
             "index": "src/index.html",
             "main": "src/main.ts",
-            "polyfills": "src/polyfills.ts",
             "tsConfig": "src/tsconfig.app.json",
             "assets": [
               "src/favicon.ico",
               "src/assets"
             ],
             "styles": [
-              "src/styles.css"
             ],
             "scripts": []
           },
@@ -68,11 +66,9 @@
           "builder": "@angular-devkit/build-angular:karma",
           "options": {
             "main": "src/test.ts",
-            "polyfills": "src/polyfills.ts",
             "tsConfig": "src/tsconfig.spec.json",
             "karmaConfig": "src/karma.conf.js",
             "styles": [
-              "styles.css"
             ],
             "scripts": [],
             "assets": [
@@ -100,4 +96,4 @@
   "cli": {
     "analytics": false
   }
-}
+}

aio/content/demos/first-app/src/main.ts

@@ -1,5 +1,5 @@
 // import required packages
-import './polyfills';
+import 'zone.js/dist/zone';
 import { Component } from '@angular/core';
 import { bootstrapApplication } from '@angular/platform-browser';
 

aio/content/demos/first-app/src/tsconfig.app.json

@@ -5,8 +5,7 @@
     "types": []
   },
   "files": [
-    "main.ts",
-    "polyfills.ts"
+    "main.ts"
   ],
   "include": [
     "**/*.d.ts"

aio/content/demos/first-app/src/tsconfig.spec.json

@@ -8,8 +8,7 @@
     ]
   },
   "files": [
-    "test.ts",
-    "polyfills.ts"
+    "test.ts"
   ],
   "include": [
     "**/*.spec.ts",