message: Update: `metamask` provider documentation
diff: @@ -277,15 +277,25 @@ import { metamask } from 'colony-wallet/providers'; // metamask();
  ### `metamask`
  ```js
  -metamask([network: string])
  +metamask([ProviderArguments: Object])
  ```
  -This provider method takes just an optional `network` name as string _(defaults to 'homestead')_ and will use the in-page `Web3` provider injected by the [Metamask extension](https://github.com/MetaMask/metamask-extension), if available.
  +This method returns an provider instance object, instantiated with the necessary prop fields.
  +
  +This provider use the in-page `Web3` provider injected by the [Metamask extension](https://github.com/MetaMask/metamask-extension), if available.
  +
  +See [`ProviderArgumentsType`](../src/flowtypes.js#L94-L98) in [`flowtypes.js`](../src/flowtypes.js) for how the arguments object looks like.
  +
  +The only _(optional)_ prop that this method will take is `network`. _(defaults to "homestead")_
  ```js
  import { metamask } from 'colony-wallet/providers';
  -const provider = metamask('homestead'); // { chainId: '', ensAddress: '', ... }
  +const provider = metamask({
  + network: 'homestead'
  +});
  +
  +// { chainId: '', ensAddress: '', ... }
  // Or just use the defaults if you just want to go on mainnet.
  const providerDefaults = metamask();
  