update readme - logo on separate line, fix ToC

Author: pushkyn

README.md

@@ -1,4 +1,5 @@
 ![SendGrid Logo](https://uiux.s3.amazonaws.com/2016-logos/email-logo%402x.png)
+
 [![Travis Badge](https://travis-ci.org/sendgrid/smtpapi-csharp.svg?branch=master)](https://travis-ci.org/sendgrid/smtpapi-csharp)
 [![Email Notifications Badge](https://dx.sendgrid.com/badge/csharp)](https://dx.sendgrid.com/newsletter/csharp)
 [![Twitter Follow](https://img.shields.io/twitter/follow/sendgrid.svg?style=social&label=Follow)](https://twitter.com/sendgrid)
@@ -15,6 +16,8 @@ All updates to this module is documented in our [CHANGELOG](https://github.com/s
 - [Installation](#installation)
 - [Quick Start](#quick-start)
 - [Usage](#usage)
+- [Roadmap](#roadmap)
+- [How to Contribute](#contribute)
 - [About](#about)
 - [License](#license)
 
@@ -108,11 +111,13 @@ mail.Headers.Add("X-SMTPAPI", header.JsonString());
 - [SendGrid Docs](https://sendgrid.com/docs/API_Reference/SMTP_API/index.html)
 - [Example Code](https://github.com/sendgrid/smtpapi-csharp/blob/master/Smtpapi/Example/Program.cs)
 
-## Roadmap
+<a name="roadmap"></a>
+# Roadmap
 
 If you are interested in the future direction of this project, please take a look at our [milestones](https://github.com/sendgrid/smtpapi-csharp/milestones). We would love to hear your feedback.
 
-## How to Contribute
+<a name="contribute"></a>
+# How to Contribute
 
 We encourage contribution to our projects, please see our [CONTRIBUTING](https://github.com/sendgrid/smtpapi-csharp/blob/master/CONTRIBUTING.md) guide for details.