remove header attributes

docs/modules/sdk/pages/sdk.adoc

@@ -1,11 +1,6 @@
 = jMonkeyEngine SDK Documentation
-:author:
-:revnumber:
-:revdate: 2016/03/17 20:48
-:experimental:
-:keywords: documentation, tool, sdk
-ifdef::env-github,env-browser[:outfilesuffix: .adoc]
-
+:revnumber:2.0
+:revdate: 2020/07/09
 
 
 == Why jMonkeyEngine SDK?