Update readme

README.md

@@ -1,13 +1,18 @@
 # LedgerStockUpdate
 
-This application locates any stocks you have in your [ledger-cli](ledger-cli.org) file, then generates a price database of those stocks compatible with the application.
+This application locates any stocks/crypto currencies you have in your [ledger-cli](https://ledger-cli.org) file, then generates a price database of those stocks compatible with the application, using quotes from Yahoo Finance.
+
+Forked from [adchari/LedgerStockUpdate](https://github.com/adchari/LedgerStockUpdate), add some features:
+* Add name mapping functionality: use BTC in your ledger and BTC-USD for online quotes
+* Replace API from Alpha Vantage, without the needs of obtaining API token
+* Recursively transform the quotes to single currency
 
 ### Usage
 
 Build the go file, and run as follows:
 
 ```bash
-./[name of executable] -f=[ledger file] -p=[price database file (to create or update)] -a=[Alpha Vantage API token] -b=[Name of ledger binary]
+./[name of executable] -f=[ledger file] -p=[price database file (to create or update)] -b=[Name of ledger binary] -m=[name mapping file]
 ```
 
 This should spit out a price database file, which can then be used to calculate the market value in ledger as follows:
@@ -15,3 +20,4 @@ This should spit out a price database file, which can then be used to calculate
 ```bash
 ledger -f [ledger file] --price-db [price database file] -V bal
 ```
+