npm #45 (#48)

* Edits on package.json #45

Add prepublishOnly https://docs.npmjs.com/misc/scripts
Add bin https://docs.npmjs.com/files/package.json#bin

* `chmod +x src/index.js`

This is required because file is run from package.json:7 bin

* Add npm install documentation #45

* Add npm badge

* Styling change by npm in package.json

* Add warning on npm global install

https://github.com/jeremija/peer-calls/pull/48#issuecomment-437192240

README.md

@@ -1,6 +1,6 @@
 # Peer Calls
 
-[![Build Status](https://travis-ci.org/jeremija/peer-calls.svg?branch=master)](https://travis-ci.org/jeremija/peer-calls)
+[![Build Status](https://travis-ci.org/jeremija/peer-calls.svg?branch=master)](https://travis-ci.org/jeremija/peer-calls) [![npm](https://img.shields.io/npm/v/peer-calls.svg)](https://www.npmjs.com/package/peer-calls)
 
 WebRTC peer to peer calls for everyone. See it live in action at
 [peercalls.com](https://peercalls.com).
@@ -12,7 +12,19 @@ Work in progress.
 
 # Installation & Running
 
-From git source:
+## From npm
+
+create directory `./peer-calls` and copy [config/default.json](https://raw.githubusercontent.com/jeremija/peer-calls/master/config/default.json) into it.
+
+```bash
+npm install --global peer-calls
+
+env NODE_CONFIG_DIR=./peer-calls peercalls
+```
+
+> :warning: Using `--global` is not advised in server environments. [*](https://github.com/jeremija/peer-calls/pull/48)
+
+## From git source
 
 ```bash
 git clone https://github.com/jeremija/peer-calls.git

package.json

@@ -4,11 +4,15 @@
   "description": "Group peer to peer video calls for anybody.",
   "repository": "https://github.com/jeremija/peer-calls",
   "main": "src/index.js",
+  "bin": {
+    "peercalls": "./src/index.js"
+  },
   "scripts": {
     "start": "node src/index.js",
     "start:server": "nodemon src/index.js --ignore build/ --ignore src/client",
     "start:watch": "chastifol [ npm run js:watch ] [ npm run css:watch ] [ npm run start:server ]",
     "watch": "",
+    "prepublishOnly": "npm run build",
     "build": "npm run css && npm run js",
     "test": "jest",
     "test:coverage": "jest --coverage",