fix version placeholder

Author: pkucmus

docs/index.md

@@ -1,7 +1,7 @@
 ---
 title: Introduction
 ---
-# EVA <sub><sup>2.1.0</sup></sub>
+# EVA <sub><sup>{{ config.version }}</sup></sub>
 
 <iframe id="player" type="text/html" width="800" height="480"
   src="https://www.youtube.com/embed/fOFlQ7dKGFQ?enablejsapi=1&origin=https://eva-3d.github.io/eva-main/"