Add webpack usage example #200

This closes #200

README.md

@@ -44,6 +44,9 @@ https://cdn.steemjs.com/lib/latest/steem.min.js<br/>
 <script src="//cdn.steemjs.com/lib/latest/steem.min.js"></script>
 ```
 
+## Webpack
+[Please have a look at the webpack usage example.](https://github.com/steemit/steem-js/blob/master/examples/webpack-example)
+
 ## Server
 ## Install
 ```

examples/webpack-example/.gitignore

+node-bundle.js
+bundle.js

examples/webpack-example/README.md

+# `steem-js` webpack configuration example
+This is a demo of `steem-js` and webpack usage targetting both the Web and
+Node.js platforms.
+
+## Minimal configuration
+`steem-js` requires JSON files internally, so you need JSON loader configured:
+```json
+{
+  ...
+  module: {
+    loaders: [
+        { test: /\.json$/, loader: 'json-loader'},
+    ]
+  }
+  ...
+}
+```
+
+Make sure `resolve.extensions` and `json-loader`'s `module.loaders[...].exclude`
+do not exclude `.json` files or `node_modules` from resolving.
+
+## Compiling the example
+Compiling for the web (`bundle.js`, which you can test with `open index.html`):
+```
+webpack
+```
+
+Compiling for node.js (`node-bundle.js`, which you can test with `node node-bundle.js`):
+```
+USE_NODE=1 webpack
+```

examples/webpack-example/index.html

+<script src="bundle.js"></script>

examples/webpack-example/package.json

+{
+  "name": "steem-js-webpack-example",
+  "scripts": {
+    "build": "npm run build-web && npm run build-node",
+    "build-web": "webpack",
+    "build-node": "USE_NODE=1 webpack"
+  },
+  "devDependencies": {
+    "json-loader": "^0.5.4",
+    "webpack": "^3.0.0"
+  },
+  "dependencies": {
+    "steem": "^0.5.20"
+  }
+}

examples/webpack-example/src/index.js

+const steem = require('steem/lib/browser');
+
+console.log('Getting post content...');
+const resultP = steem.api.getContentAsync('yamadapc', 'test-1-2-3-4-5-6-7-9');
+resultP.then(result => console.log(result));

examples/webpack-example/webpack.config.js

+module.exports = {
+  entry: './src/index.js',
+  target: process.env.USE_NODE ? 'node' : 'web',
+  output: {
+    filename: process.env.USE_NODE ? 'node-bundle.js' : 'bundle.js'
+  },
+  module: {
+    loaders: [
+        { test: /\.json$/, loader: 'json-loader'},
+    ]
+  },
+}