Added context and changed parameter structure to object

README.md

@@ -15,18 +15,36 @@ Logs the final object using passed function, Elastic URL or `Debug` library with
 const error = new ErrorCustom(message, statusCode, errorCode, baseError, logFunction);
 ```
 
-   * {string} `message`
-Error message to set on the Error object
+   * {string | IConfig} `message`
+Error message to set on the Error object, or a config object for all parameters
    * {number} `statusCode`
-HTTP status code
+HTTP status code, optional as it can be passed as part of the config
    * {number} `errorCode`
-The specific error code as defined in documentation
+The specific error code as defined in documentation, optional as it can be passed as part of the config
    * {Error} `baseError`
 Optional base exception to be included as innerException property
    * {Function|string} `logFunction`
 Optional function to log the error with. If not supplied, debug library will be used
 to log to the console with the tag `error-custom`. If a string is provided that is a
 URL, it will be used to send to that URL with ElasticSearch client in Winston format.
+   * {object} `context`
+Optional context information to provide with the error
+
+## IConfig definition
+An `Iconfig` object can be apssed instead of individual parameters as below, where the definition are the same as the constructor.
+```
+export interface IConfig {
+    message: string;
+    statusCode: number;
+    errorCode: number;
+    baseError?: Error;
+    logFunction?: string | Function;
+    context: any;
+}
+```
+
+## toJSON
+The object includes a `toJSON()` override to make all parameters iterable. Note that this returns an object, not a JSON string.
 
 ## Environment Variables
 Functionality can be modified with various environment variables: