doc: add project description to README

also add npm version badge

Author: urish

README.md

@@ -1 +1,8 @@
-Wokwi Elements
+# Wokwi Elements
+
+Web Components for Arduino and various electronic parts.
+
+[![NPM Version](https://img.shields.io/npm/v/@wokwi/elements)](https://www.npmjs.com/package/@wokwi/elements)
+
+Check out [the component catalog](https://elements.wokwi.com).
+