Merge pull request kriskowal#321 from CGamesPlay/master

Add clarification regarding Node.js CPS to README.md

README.md

@@ -684,9 +684,10 @@ return Q.fcall(function () {
 ### Adapting Node
 
 If you're working with functions that make use of the Node.js callback pattern,
-Q provides a few useful utility functions for converting between them. The
-most straightforward are probably `Q.nfcall` and `Q.nfapply` ("Node function
-call/apply") for calling Node.js-style functions and getting back a promise:
+where callbacks are in the form of `function(err, result)`, Q provides a few
+useful utility functions for converting between them. The most straightforward
+are probably `Q.nfcall` and `Q.nfapply` ("Node function call/apply") for calling
+Node.js-style functions and getting back a promise:
 
 ```javascript
 return Q.nfcall(FS.readFile, "foo.txt", "utf-8");