add svg instead png to README

README.md

@@ -1,8 +1,8 @@
 <div align="center">
-    <img src=".github/logo.png" height="128">
+    <img src="https://raw.githubusercontent.com/frappe/design/master/logos/frappe-charts-symbol.svg" height="128">
     <h2>Frappé Charts</h2>
     <p align="center">
-        <p>A <b>zero-dependency</b> GitHub-inspired modern, intuitive and responsive charting library</p>
+        <p>GitHub-inspired modern, intuitive and responsive charts with zero-dependency</p>
         <a href="https://frappe.github.io/charts">
             <b>Explore the Demos »</b>
         </a>