fix: replace 2.X.Y with 4.X.Y

Author: IgorMinar

public/_includes/_hero.jade

@@ -15,7 +15,7 @@ if current.path[4] && current.path[3] == 'api'
 
 if current.path.indexOf('cheatsheet') > 0 || current.path[current.path.length-2] === 'api'
   - var base = current.path[4] ? '../guide' : './guide';
-  - var ngVersion = '(v<ngio-cheatsheet src="' + base + '/cheatsheet.json" version-only>2.X.Y</ngio-cheatsheet>)'; 
+  - var ngVersion = '(v<ngio-cheatsheet src="' + base + '/cheatsheet.json" version-only>4.X.Y</ngio-cheatsheet>)';
 
 header.hero.background-sky
   h1(class="hero-title #{textFormat}") #{headerTitle} !{ngVersion}