Add Config class

NodeApp/src/Config/Config.ts

+import * as os from 'os';
+
+
+class Config {
+    private static _instance: Config;
+
+    public readonly apiURL: string;
+
+    public readonly localConfig: {
+        folder: string; file: string;
+    };
+
+    private constructor() {
+        this.apiURL = process.env.API_URL || '';
+
+        this.localConfig = {
+            folder: (process.env.LOCAL_CONFIG_FOLDER || '').replace('~', os.homedir()),
+            file  : process.env.LOCAL_CONFIG_FILE || ''
+        };
+    }
+
+    public static get instance(): Config {
+        if ( !Config._instance ) {
+            Config._instance = new Config();
+        }
+
+        return Config._instance;
+    }
+}
+
+
+export default Config.instance;