message: Add: wallet object `subtype` prop documentation
diff: @@ -19,6 +19,7 @@ WalletInstance {
  privateKeyQR: Promise<String>, // deprecated
  provider: Object, // deprecated
  type: String,
  + subtype: String,
  /*
  * Methods
  */
  @@ -28,7 +29,7 @@ WalletInstance {
  This is the complete form of the Wallet Object, but in some cases, values are not going to be set due to various constraints.
  -_**Example:** Instantiating a software wallet using an existing `private key` will not set the `mnemonic` since it's value cannot be reversed. But instantiating a software wallet using a `mnemonic` phrase will also set the `privateKey`s prop value since that can be reversed._
  +_**Example:** Instantiating a software wallet using an existing `privateKey` will not set the `mnemonic` since it's value cannot be reversed. But instantiating a software wallet using a `mnemonic` phrase will also set the `privateKey`s prop value since that can be reversed._
  ## Contents:
  @@ -45,6 +46,7 @@ _**Example:** Instantiating a software wallet using an existing `private key` wi
  * [`privateKeyQR`](#privatekeyqr)
  * [`provider`](#provider)
  * [`type`](#type)
  + * [`subtype`](#subtype)
  * Methods
  * [`sendWithConfirmation()`](#sendwithconfirmation)
  @@ -278,6 +280,21 @@ const wallet = await create();
  console.log(wallet.type); // software
  ```
  +### `subtype`
  +```js
  +WalletInstance.subtype: String
  +```
  +
  +This is just a simple string value that represents the sub type for _(wallet type engine)_ the instantiated wallet object.
  +
  +```js
  +import { create } from 'colony-wallet/software';
  +
  +const wallet = await create();
  +
  +console.log(wallet.subtype); // ethers
  +```
  +
  ## Methods
  ### `sendWithConfirmation()`
  