Update README with instructions for environment variables

README.md

@@ -38,10 +38,23 @@ The below instructions are geared toward BTC, but can be adapted easily to other
 1. Clone this repo: `git clone https://github.com/janoside/btc-rpc-explorer`
 2. `npm install`
 3. `npm run build`
-4. Optional: Create git-ignored file `app/credentials.js` with values to overwrite those in [app/defaultCredentials.js](app/defaultCredentials.js).
-5. Optional: Change the "coin" value in [app/config.js](app/config.js). Currently supported values are "BTC" and "LTC".
-6. `npm start`
-7. Open [http://127.0.0.1:3002/](http://127.0.0.1:3002/)
+4. Set environment variables with your bitcoind rpc credentials and other settings. See [configuration](#configuration).
+5. `npm start`
+6. Open [http://127.0.0.1:3002/](http://127.0.0.1:3002/)
+
+### Configuration
+
+Configuration options may be passed as environment variables.
+You can also set them in a `.env` file in the root directory, in the following format:
+
+```
+BTCEXP_BITCOIND_HOST = localhost
+BTCEXP_BITCOIND_PORT = 8332
+BTCEXP_BITCOIND_USER = username
+BTCEXP_BITCOIND_PASS = password
+BTCEXP_IPSTACK_KEY = 0000aaaafffffgggggg
+BTCEXP_COOKIEPASSWORD = 0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
+```
 
 ## Run via Docker