add note about CouchDB compat

Author: thehunmonkgroup

README.md

@@ -2,9 +2,11 @@
 
 Lua API for [CouchDB](http://couchdb.apache.org).
 
- * Compatible with Lua 5.1, 5.2, 5.3
+ * Compatible with Lua 5.1, 5.2, 5.3, 5.4
  * 100% unit test coverage
 
+*NOTE: 1.x branch is no longer maintained. It is compatible with CouchDb 2.x and earlier.*
+
 ## Installation:
 
 It is recommended to install the [LuaRocks](http://luarocks.org) package