Add twitter badge to readme (#542)

* Add twitter badge to readme

* Update README.md

README.md

@@ -1,8 +1,11 @@
 <div align="center" style="display:flex;flex-direction:column;">
-    <a href="https://excalidraw.com">
-        <img src="./public/og-image.png" alt="Excalidraw logo: Sketch handrawn like diagrams." />
-    </a>
-    <h3>Excalidraw is a whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.</h3>
+  <a href="https://excalidraw.com">
+    <img src="./public/og-image.png" alt="Excalidraw logo: Sketch handrawn like diagrams." />
+  </a>
+  <h3>Excalidraw is a whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.</h3>
+  <a href="https://twitter.com/Excalidraw">
+    <img alt="Follow Excalidraw on Twitter" src="https://img.shields.io/twitter/follow/excalidraw.svg?label=follow+excalidraw&style=flat-square&logo=twitter">
+  </a>
 </div>
 
 ## Try it now