Upgrade to angular 12 (#42)

* removed the old ng-packagr dependency

- `@angular-devkit/build-ng-packagr` is already deprecated since Angular
  11, and migrated over to `@angular-devkit/build-angular`

* upgrade to angular 12

- fixed the circular import during the build for the keyboard module
- updated the tsconfig for prod, to partial Ivy compilation as
  recommended by the angular docs

* bump version number

Author: altbdoor

angular.json

@@ -22,15 +22,20 @@
             "main": "src/main.ts",
             "polyfills": "src/polyfills.ts",
             "tsConfig": "tsconfig.app.json",
-            "aot": true,
             "assets": [
               "src/favicon.ico",
               "src/assets"
             ],
             "styles": [
               "src/styles.scss"
             ],
-            "scripts": []
+            "scripts": [],
+            "vendorChunk": true,
+            "extractLicenses": false,
+            "buildOptimizer": false,
+            "sourceMap": true,
+            "optimization": false,
+            "namedChunks": true
           },
           "configurations": {
             "production": {
@@ -60,7 +65,8 @@
                 }
               ]
             }
-          }
+          },
+          "defaultConfiguration": ""
         },
         "serve": {
           "builder": "@angular-devkit/build-angular:dev-server",
@@ -130,7 +136,7 @@
       "prefix": "tb",
       "architect": {
         "build": {
-          "builder": "@angular-devkit/build-ng-packagr:build",
+          "builder": "@angular-devkit/build-angular:ng-packagr",
           "options": {
             "tsConfig": "projects/angular-keyboard/tsconfig.lib.json",
             "project": "projects/angular-keyboard/ng-package.json"