doc: fix spelling error in feature flags

PR-URL: #1286
Reviewed-By: Ben Noordhuis <[email protected]>

Author: phlco

doc/iojs.1

@@ -81,7 +81,7 @@ If set to 1 then colors will not be used in the REPL.
         type: bool  default: false
   --harmony (enable all completed harmony features)
         type: bool  default: false
-  --harmony_shipping (enable all shipped harmony fetaures)
+  --harmony_shipping (enable all shipped harmony features)
         type: bool  default: true
   --harmony_modules (enable "harmony modules (implies block scoping)" (in progress))
         type: bool  default: false