message: Add: wallet object `derivationPath` prop documentation
diff: @@ -14,7 +14,7 @@ WalletInstance {
  keystore: Promise<String>,
  mnemonic: String,
  path?: String, // deprecated, will be renamed to `derivationPath`
  - derivationath?: Promise<String>,
  + derivationPath?: Promise<String>,
  privateKey: String,
  privateKeyQR: Promise<String>, // deprecated
  provider: Object, // deprecated
  @@ -42,6 +42,7 @@ _**Example:** Instantiating a software wallet using an existing `privateKey` wil
  * [`keystore`](#keystore)
  * [`mnemonic`](#mnemonic)
  * [`path`](#path)
  + * [`derivationPath`](#derivationpath)
  * [`privateKey`](#privatekey)
  * [`privateKeyQR`](#privatekeyqr)
  * [`provider`](#provider)
  @@ -191,16 +192,36 @@ WalletInstance.path: String
  **_The `path` prop is deprecated and will be renamed to `derivationPath`, so make sure you don't rely on it too much_**
  -Contains the [BIP32](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki) [derivation path](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#specification-key-derivation) in the form of a `String`. When instantiating a wallet using a `mnemonic` phrase, this is used to re-create the `private key`.
  +See: [`derivationPath`](#derivationpath)
  -This defaults to `m/44'/60'/0'/0/0`, but can be manually set when creating the wallet instance.
  +### `derivationPath`
  +```js
  +WalletInstance.derivationPath: Promise<String>
  +```
  +
  +This is a `getter` that returns a `Promise`. Upon resolving, the promise returns a [BIP32](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki) [derivation path](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#specification-key-derivation) in the form of a `String`.
  +
  +When instantiating a software wallet using a `mnemonic` phrase, this is used to re-create the `privateKey`. This defaults to `m/44'/60'/0'/0/0`, but can be manually set when creating the wallet instance.
  +
  +On a hardware wallet, this is read-only, and is used to derive all the address indexes.
  ```js
  import { open } from 'colony-wallet/software';
  const wallet = await open({ mnemonic: 'load blush spray dirt random cash pear illness pulse sketch sheriff surge' });
  -console.log(wallet.path); // m/44'/60'/0'/0/0
  +console.log(await wallet.derivationPath); // m/44'/60'/0'/0/0
  +```
  +```js
  +import { open } from 'colony-wallet/hardware/trezor';
  +
  +const wallet = await open();
  +
  +console.log(await wallet.derivationPath); // m/44'/60'/0'/0/0
  +
  +walet.setDefaultAddress(1);
  +
  +console.log(await wallet.derivationPath); // m/44'/60'/0'/0/1
  ```
  ### `privateKey`
  