[api-platform/core] add 3.0 default configuration (#1125)

Author: soyuka

api-platform/core/3.0/config/routes/api_platform.yaml

@@ -0,0 +1,4 @@
+api_platform:
+    resource: .
+    type: api_platform
+    prefix: /api

api-platform/core/3.0/manifest.json

@@ -0,0 +1,9 @@
+{
+    "bundles": {
+        "ApiPlatform\\Symfony\\Bundle\\ApiPlatformBundle": ["all"]
+    },
+    "copy-from-recipe": {
+        "config/": "%CONFIG_DIR%/",
+        "src/": "%SRC_DIR%/"
+    }
+}

api-platform/core/3.0/post-install.txt

@@ -0,0 +1,8 @@
+  * Your API is almost ready:
+    1. Create your first API resource in <info>src/ApiResource</info>;
+    2. Go to <info>/api</info> to browse your API
+
+  * To enable the GraphQL support, run <comment>composer require webonyx/graphql-php</>,
+    then browse <info>/api/graphql</info>.
+
+  * <fg=blue>Read</> the documentation at <comment>https://api-platform.com/docs</>