[DOCS] Add EOL notice. (#1402)

debadair · debadair · commit 4498f21317ed · 2019-12-09T15:59:34.000-08:00
diff --git a/docs/src/reference/asciidoc/page_header.html b/docs/src/reference/asciidoc/page_header.html
@@ -0,0 +1,10 @@
+<p>
+  <strong>WARNING</strong>: Version 6.2 has passed its 
+  <a href="https://www.elastic.co/support/eol">EOL date</a>. 
+</p>  
+<p>
+  This documentation is no longer being maintained and may be removed. 
+  If you are running this version, we strongly advise you to upgrade. 
+  For the latest information, see the 
+  <a href="../current/index.html">current release documentation</a>. 
+</p>
