ci: use prettier to format yml files (angular#42136)

Use prettier to format all yml files in the repo via the ng-dev format tooling.

PR Close angular#42136

.ng-dev/format.ts

@@ -4,6 +4,11 @@ import {FormatConfig} from '../dev-infra/format/config';
  * Configuration for the `ng-dev format` command.
  */
 export const format: FormatConfig = {
+  'prettier': {
+    'matchers': [
+      '**/*.{yaml,yml}',
+    ]
+  },
   'clang-format': {
     'matchers': [
       '**/*.{js,ts}',

.prettierrc

@@ -0,0 +1,9 @@
+{
+  "printWidth": 100,
+  "tabWidth": 2,
+  "tabs": false,
+  "singleQuote": true,
+  "semicolon": true,
+  "quoteProps": "preserve",
+  "bracketSpacing": false
+}

package.json

@@ -194,6 +194,7 @@
     "mutation-observer": "^1.0.3",
     "nock": "^13.0.3",
     "ora": "^5.0.0",
+    "prettier": "^2.3.0",
     "rollup-plugin-hashbang": "^2.2.2",
     "sauce-connect": "https://saucelabs.com/downloads/sc-4.6.2-linux.tar.gz",
     "semver": "^7.3.5",

yarn.lock

@@ -10800,6 +10800,11 @@ prepend-http@^2.0.0:
   resolved "https://registry.yarnpkg.com/prepend-http/-/prepend-http-2.0.0.tgz#e92434bfa5ea8c19f41cdfd401d741a3c819d897"
   integrity sha1-6SQ0v6XqjBn0HN/UAddBo8gZ2Jc=
 
+prettier@^2.3.0:
+  version "2.3.0"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.3.0.tgz#b6a5bf1284026ae640f17f7ff5658a7567fc0d18"
+  integrity sha512-kXtO4s0Lz/DW/IJ9QdWhAf7/NmPWQXkFr/r/WkR3vyI+0v8amTDxiaQSLzs8NBlytfLWX/7uQUMIW677yLKl4w==
+
 pretty-bytes@^5.3.0:
   version "5.6.0"
   resolved "https://registry.yarnpkg.com/pretty-bytes/-/pretty-bytes-5.6.0.tgz#356256f643804773c82f64723fe78c92c62beaeb"
@@ -11880,7 +11885,6 @@ sauce-connect-launcher@^1.2.4:
 
 "sauce-connect@https://saucelabs.com/downloads/sc-4.6.2-linux.tar.gz":
   version "0.0.0"
-  uid "7b7f35433af9c3380758e048894d7b9aecf3754e"
   resolved "https://saucelabs.com/downloads/sc-4.6.2-linux.tar.gz#7b7f35433af9c3380758e048894d7b9aecf3754e"
 
 saucelabs@^1.5.0: