Add prettier config

.prettierignore

@@ -0,0 +1,3 @@
+docs
+dist
+node_modules

.prettierrc.json

@@ -0,0 +1,3 @@
+{
+  "trailingComma": "all"
+}

package.json

@@ -20,6 +20,7 @@
     "jest": "^26.6.3",
     "jest-marbles": "^2.5.1",
     "ng-packagr": "^11.2.4",
+    "prettier": "^2.2.1",
     "rxjs": ">= 6.5.0",
     "ts-jest": "^26.5.3",
     "tslib": "^2.1.0",

yarn.lock

@@ -30,12 +30,10 @@
   dependencies:
     tslib "^2.0.0"
 
-"@angular/core@^11.2.4":
-  version "11.2.4"
-  resolved "https://registry.yarnpkg.com/@angular/core/-/core-11.2.4.tgz#f655f05ebb245ff83c49f563193a8496afc9a36a"
-  integrity sha512-MU2DxGJOMLS6rqrakzEKJ2s+CYamM5ETBInqx4uTBJYsek3byF9gbjM6221lv8tal5dMAibigB0UuhXr23rhcQ==
-  dependencies:
-    tslib "^2.0.0"
+"@angular/core@>= 8.0.0 < 10.0":
+  version "9.1.13"
+  resolved "https://registry.yarnpkg.com/@angular/core/-/core-9.1.13.tgz#a87bc5a7926a50aec0bfcead769078bc7f1b93fa"
+  integrity sha512-mBm24Q9GjkAsxMAzqQ86U1078+yTEpr0+syMEruUtJ0HUH6Fzn3J+6xTLb+BVcGb9RkCkFaV9T5mcn6ZM0f++g==
 
 "@babel/[email protected]":
   version "7.12.11"
@@ -5005,6 +5003,11 @@ prelude-ls@~1.1.2:
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.1.2.tgz#21932a549f5e52ffd9a827f570e04be62a97da54"
   integrity sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ=
 
+prettier@^2.2.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.2.1.tgz#795a1a78dd52f073da0cd42b21f9c91381923ff5"
+  integrity sha512-PqyhM2yCjg/oKkFPtTGUojv7gnZAoG80ttl45O6x2Ug/rMJw4wcc9k6aaf2hibP7BGVCCM33gZoGjyvt9mm16Q==
+
 pretty-format@^24.9.0:
   version "24.9.0"
   resolved "https://registry.yarnpkg.com/pretty-format/-/pretty-format-24.9.0.tgz#12fac31b37019a4eea3c11aa9a959eb7628aa7c9"
@@ -5329,20 +5332,20 @@ run-parallel@^1.1.9:
   dependencies:
     queue-microtask "^1.2.2"
 
+"rxjs@>= 6.5.0":
+  version "6.6.6"
+  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-6.6.6.tgz#14d8417aa5a07c5e633995b525e1e3c0dec03b70"
+  integrity sha512-/oTwee4N4iWzAMAL9xdGKjkEHmIwupR3oXbQjCKywF1BeFohswF3vZdogbmEF6pZkOsXTzWkrZszrWpQTByYVg==
+  dependencies:
+    tslib "^1.9.0"
+
 rxjs@^6.5.0:
   version "6.5.5"
   resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-6.5.5.tgz#c5c884e3094c8cfee31bf27eb87e54ccfc87f9ec"
   integrity sha512-WfQI+1gohdf0Dai/Bbmk5L5ItH5tYqm3ki2c5GdWhKjalzjg93N3avFjVStyZZz+A2Em+ZxKH5bNghw9UeylGQ==
   dependencies:
     tslib "^1.9.0"
 
-rxjs@^6.6.6:
-  version "6.6.6"
-  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-6.6.6.tgz#14d8417aa5a07c5e633995b525e1e3c0dec03b70"
-  integrity sha512-/oTwee4N4iWzAMAL9xdGKjkEHmIwupR3oXbQjCKywF1BeFohswF3vZdogbmEF6pZkOsXTzWkrZszrWpQTByYVg==
-  dependencies:
-    tslib "^1.9.0"
-
 safe-buffer@^5.0.1, safe-buffer@^5.1.2, safe-buffer@~5.2.0:
   version "5.2.1"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.2.1.tgz#1eaf9fa9bdb1fdd4ec75f58f9cdb4e6b7827eec6"