default to mainnet

Author: Zach Alam

README.md

@@ -33,8 +33,9 @@ yarn add bitfact
 const bitfact = new BitFact({ 
   provider: "https://mainnet.infura.io/v3/37a0db22401bbe211112",
   privateKey: "321d3fa232e55dedee2bd914273f78897f69053b61437c5"
-});
+}, {chain: 'mainnet'});
 ```
+*Optional* 2nd Parameter: **chain** can be of value `mainnet` or `ropsten`. If ignored, `mainnet` will be used.
 
 #### ❇️ Snippet #1: Fingerprint text or raw data.
 ```javascript

config.js

@@ -1,4 +1,4 @@
 module.exports = {
     BITFACT_ADDR: "0xface74F0D85CF2FC5a7cd4f55258493c0535F89B",
-    DEFAULT_CHAIN: {chain: 'ropsten'}
+    DEFAULT_CHAIN: {chain: 'mainnet'}
 }