added frontend and made it usable

frontend/config/bundles.php

@@ -0,0 +1,7 @@
+<?php
+
+return [
+    Symfony\Bundle\FrameworkBundle\FrameworkBundle::class => ['all' => true],
+    Doctrine\Bundle\DoctrineBundle\DoctrineBundle::class => ['all' => true],
+    Symfony\Bundle\TwigBundle\TwigBundle::class => ['all' => true],
+];

frontend/config/packages/doctrine.yaml

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+doctrine:
+    dbal:
+        url: '%env(resolve:DATABASE_URL)%'
+        server_version: '14'
+    orm:
+        auto_generate_proxy_classes: true
+        enable_lazy_ghost_objects: true
+        report_fields_where_declared: true
+        validate_xml_mapping: true
+        naming_strategy: doctrine.orm.naming_strategy.underscore_number_aware
+        auto_mapping: true
+        mappings:
+            App:
+                type: attribute
+                is_bundle: false
+                dir: '%kernel.project_dir%/src/Entity'
+                prefix: 'App\Entity'
+                alias: App
+        controller_resolver:
+            auto_mapping: true
+
+when@test:
+    doctrine:
+        dbal:
+            dbname_suffix: '_test%env(default::TEST_TOKEN)%'
+
+when@prod:
+    doctrine:
+        orm:
+            auto_generate_proxy_classes: false
+            proxy_dir: '%kernel.build_dir%/doctrine/orm/Proxies'
+            query_cache_driver:
+                type: pool
+                pool: doctrine.system_cache_pool
+            result_cache_driver:
+                type: pool
+                pool: doctrine.result_cache_pool
+
+    framework:
+        cache:
+            pools:
+                doctrine.result_cache_pool:
+                    adapter: cache.app
+                doctrine.system_cache_pool:
+                    adapter: cache.system

frontend/config/packages/framework.yaml

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+framework:
+    secret: '%env(APP_SECRET)%'
+    router:
+        utf8: true
+    php_errors:
+        log: true
+    assets: ~

frontend/config/packages/twig.yaml

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+twig:
+    default_path: '%kernel.project_dir%/templates'
+
+when@test:
+    twig:
+        strict_variables: true

frontend/config/routes.yaml

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+controllers:
+    resource:
+        path: ../src/Controller/
+        namespace: App\Controller
+    type: attribute

frontend/config/services.yaml

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+parameters:
+
+services:
+    _defaults:
+        autowire: true
+        autoconfigure: true
+
+    App\:
+        resource: '../src/'
+        exclude:
+            - '../src/DependencyInjection/'
+            - '../src/Entity/'
+            - '../src/Kernel.php'