Setup docs-builder

It is necessary to run the Documentation workflow.

composer.json

@@ -64,5 +64,8 @@
             "dealerdirect/phpcodesniffer-composer-installer": true
         },
         "sort-packages": true
+    },
+    "scripts": {
+        "docs": "composer --working-dir docs update && ./docs/vendor/bin/build-docs.sh @additional_args"
     }
 }

docs/.gitignore

@@ -0,0 +1,3 @@
+/composer.lock
+/vendor/
+/output/

docs/composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "doctrine/docs-builder": "^1.0"
+    }
+}