Change 2.18 to correct version (#2089)

Author: samccann

docs/docsite/rst/conf.py

@@ -44,7 +44,7 @@
 
 VERSION = (
      # Controls branch version for core releases
-    'devel' if tags.has('core_lang') or tags.has('core') else
+    '2.18' if tags.has('core_lang') or tags.has('core') else
     # Controls branch version for Ansible package releases
     'devel' if tags.has('ansible') or tags.has('all')
     else '<UNKNOWN>'