feature #21 Add a recipe to install API Platform (dunglas)

This PR was squashed before being merged into the master branch (closes #21).

Discussion
----------

Add a recipe to install API Platform

But I've no idea of how to test it 😅

Commits
-------

a55986d Add a recipe to install API Platform

Author: fabpot

api-platform/api-pack/2.1/manifest.json

@@ -0,0 +1,3 @@
+{
+    "aliases": ["api", "api-platform"]
+}

api-platform/core/2.1/etc/packages/api_platform.yaml

@@ -0,0 +1,3 @@
+api_platform:
+    loader_paths:
+        annotation: ["%kernel.project_dir%/src/Entity"]

api-platform/core/2.1/etc/routing/api_platform.yaml

@@ -0,0 +1,3 @@
+api_platform:
+    resource: .
+    type: api_platform

api-platform/core/2.1/manifest.json

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