feat: add Swagger UI docs at /api_info endpoint

web/swagger/swagger-initializer.js

@@ -0,0 +1,19 @@
+window.onload = function() {
+  //<editor-fold desc="Changeable Configuration Block">
+
+  // the following lines will be replaced by docker/configurator, when it runs in a docker-container
+  window.ui = SwaggerUIBundle({
+    url: "/swagger/swagger.yaml",
+    dom_id: '#swagger-ui',
+    deepLinking: false,
+    presets: [
+      SwaggerUIBundle.presets.apis
+    ],
+    plugins: [
+      SwaggerUIBundle.plugins.DownloadUrl
+    ],
+    layout: "BaseLayout"
+  });
+
+  //</editor-fold>
+};