Added documentation

types/nodegit/submodule-update-options.d.ts

@@ -2,8 +2,32 @@ import { CheckoutOptions } from './checkout-options';
 import { FetchOptions } from './fetch-options';
 
 export interface SubmoduleUpdateOptions {
+    /**
+     *
+     *
+     * @type {number}
+     * @memberof SubmoduleUpdateOptions
+     */
     version?: number;
+    /**
+     *
+     *
+     * @type {CheckoutOptions}
+     * @memberof SubmoduleUpdateOptions
+     */
     checkoutOpts?: CheckoutOptions;
+    /**
+     *
+     *
+     * @type {FetchOptions}
+     * @memberof SubmoduleUpdateOptions
+     */
     fetchOpts?: FetchOptions;
+    /**
+     *
+     *
+     * @type {number}
+     * @memberof SubmoduleUpdateOptions
+     */
     cloneCheckoutStrategy?: number;
 }