doc: move stray sentences in zlib doc

Move mislocated sentences to correct location.

PR-URL: https://github.com/nodejs/node/pull/9365
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

doc/api/zlib.md

@@ -384,13 +384,13 @@ Only applicable to deflate algorithm.
 added: v0.7.0
 -->
 
+Reset the compressor/decompressor to factory defaults. Only applicable to
+the inflate and deflate algorithms.
+
 ## zlib.constants
 
 Provides an object enumerating Zlib-related constants.
 
-Reset the compressor/decompressor to factory defaults. Only applicable to
-the inflate and deflate algorithms.
-
 ## zlib.createDeflate([options])
 <!-- YAML
 added: v0.5.8