Update description of config slightly

Author: AdrianCurtin

src/Adapters/Files/FilesAdapter.js

@@ -33,8 +33,8 @@ export class FilesAdapter {
    * - tags: object containing key value pairs that will be stored with file
    * - metadata: object containing key value pairs that will be stored with file (https://docs.aws.amazon.com/AmazonS3/latest/user-guide/add-object-metadata.html)
    * @discussion options are not supported by all file adapters. Check the your adapter's documentation for compatibility
-   * @param {Config} config -(Optional) server configuration
-   * @discussion config is not supported by all file adapters. Check the your adapter's documentation for compatibility
+   * @param {Config} config - (Optional) server configuration
+   * @discussion config may be passed to adapter to allow for more complex configuration and internal call of getFileLocation (if needed). This argument is not supported by all file adapters. Check the your adapter's documentation for compatibility
    *
    * @return {Promise<{url?: string, name?: string, location?: string}>|Promise<undefined>} Either a plain promise that should fail if storage didn't succeed, or a promise resolving to an object containing url and/or an updated filename and/or location (if relevant)
    */